--- a/b2g/app/b2g.js
+++ b/b2g/app/b2g.js
@@ -183,19 +183,16 @@ pref("privacy.item.history", true);
 pref("privacy.item.formdata", true);
 pref("privacy.item.downloads", true);
 pref("privacy.item.passwords", true);
 pref("privacy.item.sessions", true);
 pref("privacy.item.geolocation", true);
 pref("privacy.item.siteSettings", true);
 pref("privacy.item.syncAccount", true);
 
-// URL to the Learn More link XXX this is the firefox one.  Bug 495578 fixes this.
-pref("browser.geolocation.warning.infoURL", "http://www.mozilla.com/%LOCALE%/firefox/geolocation/");
-
 // base url for the wifi geolocation network provider
 pref("geo.wifi.uri", "https://maps.googleapis.com/maps/api/browserlocation/json");
 
 // enable geo
 pref("geo.enabled", true);
 
 // content sink control -- controls responsiveness during page load
 // see https://bugzilla.mozilla.org/show_bug.cgi?id=481566#c9
@@ -337,17 +334,16 @@ pref("browser.safebrowsing.provider.0.ge
 // HTML report pages
 pref("browser.safebrowsing.provider.0.reportGenericURL", "http://{moz:locale}.phish-generic.mozilla.com/?hl={moz:locale}");
 pref("browser.safebrowsing.provider.0.reportErrorURL", "http://{moz:locale}.phish-error.mozilla.com/?hl={moz:locale}");
 pref("browser.safebrowsing.provider.0.reportPhishURL", "http://{moz:locale}.phish-report.mozilla.com/?hl={moz:locale}");
 pref("browser.safebrowsing.provider.0.reportMalwareURL", "http://{moz:locale}.malware-report.mozilla.com/?hl={moz:locale}");
 pref("browser.safebrowsing.provider.0.reportMalwareErrorURL", "http://{moz:locale}.malware-error.mozilla.com/?hl={moz:locale}");
 
 // FAQ URLs
-pref("browser.geolocation.warning.infoURL", "http://www.mozilla.com/%LOCALE%/%APP%/geolocation/");
 
 // Name of the about: page contributed by safebrowsing to handle display of error
 // pages on phishing/malware hits.  (bug 399233)
 pref("urlclassifier.alternate_error_page", "blocked");
 
 // The number of random entries to send with a gethash request.
 pref("urlclassifier.gethashnoise", 4);
 

--- a/b2g/config/emulator-ics/sources.xml
+++ b/b2g/config/emulator-ics/sources.xml
@@ -7,17 +7,17 @@
   <remote fetch="https://git.mozilla.org/releases" name="mozillaorg"/>
   <remote fetch="https://git.mozilla.org/external/apitrace" name="apitrace"/>
   <default remote="caf" revision="refs/tags/android-4.0.4_r2.1" sync-j="4"/>
   <!-- Gonk specific things and forks -->
   <project name="platform_build" path="build" remote="b2g" revision="59605a7c026ff06cc1613af3938579b1dddc6cfe">
     <copyfile dest="Makefile" src="core/root.mk"/>
   </project>
   <project name="fake-dalvik" path="dalvik" remote="b2g" revision="ca1f327d5acc198bb4be62fa51db2c039032c9ce"/>
-  <project name="gaia.git" path="gaia" remote="mozillaorg" revision="e0b7c709ddc21c407ee3360d3203e9eb84535b66"/>
+  <project name="gaia.git" path="gaia" remote="mozillaorg" revision="8d18b1e2fd06c84a879f99f6e8ca1f104eeacb13"/>
   <project name="gonk-misc" path="gonk-misc" remote="b2g" revision="e9b6626eddbc85873eaa2a9174a9bd5101e5c05f"/>
   <project name="rilproxy" path="rilproxy" remote="b2g" revision="827214fcf38d6569aeb5c6d6f31cb296d1f09272"/>
   <project name="platform_hardware_ril" path="hardware/ril" remote="b2g" revision="eda08beb3ba9a159843c70ffde0f9660ec351eb9"/>
   <project name="platform_external_qemu" path="external/qemu" remote="b2g" revision="87aa8679560ce09f6445621d6f370d9de722cdba"/>
   <project name="moztt" path="external/moztt" remote="b2g" revision="96d2d00165f4561fbde62d1062706eab74b3a01f"/>
   <project name="apitrace" path="external/apitrace" remote="apitrace" revision="e2f73049f8d52fb06cb9b5d923c1280557aa9238"/>
   <!-- Stock Android things -->
   <project name="platform/abi/cpp" path="abi/cpp" revision="dd924f92906085b831bf1cbbc7484d3c043d613c"/>

--- a/b2g/config/emulator-jb/sources.xml
+++ b/b2g/config/emulator-jb/sources.xml
@@ -6,17 +6,17 @@
   <remote fetch="https://git.mozilla.org/external/caf" name="caf"/>
   <remote fetch="https://git.mozilla.org/releases" name="mozillaorg"/>
   <!-- B2G specific things. -->
   <project name="platform_build" path="build" remote="b2g" revision="fce1a137746dbd354bca1918f02f96d51c40bad2">
     <copyfile dest="Makefile" src="core/root.mk"/>
   </project>
   <project name="rilproxy" path="rilproxy" remote="b2g" revision="827214fcf38d6569aeb5c6d6f31cb296d1f09272"/>
   <project name="fake-libdvm" path="dalvik" remote="b2g" revision="d50ae982b19f42f0b66d08b9eb306be81687869f"/>
-  <project name="gaia" path="gaia" remote="mozillaorg" revision="e0b7c709ddc21c407ee3360d3203e9eb84535b66"/>
+  <project name="gaia" path="gaia" remote="mozillaorg" revision="8d18b1e2fd06c84a879f99f6e8ca1f104eeacb13"/>
   <project name="gonk-misc" path="gonk-misc" remote="b2g" revision="e9b6626eddbc85873eaa2a9174a9bd5101e5c05f"/>
   <project name="moztt" path="external/moztt" remote="b2g" revision="96d2d00165f4561fbde62d1062706eab74b3a01f"/>
   <project name="apitrace" path="external/apitrace" remote="apitrace" revision="e2f73049f8d52fb06cb9b5d923c1280557aa9238"/>
   <project name="valgrind" path="external/valgrind" remote="b2g" revision="905bfa3548eb75cf1792d0d8412b92113bbd4318"/>
   <project name="vex" path="external/VEX" remote="b2g" revision="c3d7efc45414f1b44cd9c479bb2758c91c4707c0"/>
   <!-- Stock Android things -->
   <project groups="linux" name="platform/prebuilts/clang/linux-x86/3.1" path="prebuilts/clang/linux-x86/3.1" revision="5c45f43419d5582949284eee9cef0c43d866e03b"/>
   <project groups="linux" name="platform/prebuilts/clang/linux-x86/3.2" path="prebuilts/clang/linux-x86/3.2" revision="3748b4168e7bd8d46457d4b6786003bc6a5223ce"/>

--- a/b2g/config/emulator/sources.xml
+++ b/b2g/config/emulator/sources.xml
@@ -7,17 +7,17 @@
   <remote fetch="https://git.mozilla.org/releases" name="mozillaorg"/>
   <remote fetch="https://git.mozilla.org/external/apitrace" name="apitrace"/>
   <default remote="caf" revision="refs/tags/android-4.0.4_r2.1" sync-j="4"/>
   <!-- Gonk specific things and forks -->
   <project name="platform_build" path="build" remote="b2g" revision="59605a7c026ff06cc1613af3938579b1dddc6cfe">
     <copyfile dest="Makefile" src="core/root.mk"/>
   </project>
   <project name="fake-dalvik" path="dalvik" remote="b2g" revision="ca1f327d5acc198bb4be62fa51db2c039032c9ce"/>
-  <project name="gaia.git" path="gaia" remote="mozillaorg" revision="e0b7c709ddc21c407ee3360d3203e9eb84535b66"/>
+  <project name="gaia.git" path="gaia" remote="mozillaorg" revision="8d18b1e2fd06c84a879f99f6e8ca1f104eeacb13"/>
   <project name="gonk-misc" path="gonk-misc" remote="b2g" revision="e9b6626eddbc85873eaa2a9174a9bd5101e5c05f"/>
   <project name="rilproxy" path="rilproxy" remote="b2g" revision="827214fcf38d6569aeb5c6d6f31cb296d1f09272"/>
   <project name="platform_hardware_ril" path="hardware/ril" remote="b2g" revision="eda08beb3ba9a159843c70ffde0f9660ec351eb9"/>
   <project name="platform_external_qemu" path="external/qemu" remote="b2g" revision="87aa8679560ce09f6445621d6f370d9de722cdba"/>
   <project name="moztt" path="external/moztt" remote="b2g" revision="96d2d00165f4561fbde62d1062706eab74b3a01f"/>
   <project name="apitrace" path="external/apitrace" remote="apitrace" revision="e2f73049f8d52fb06cb9b5d923c1280557aa9238"/>
   <!-- Stock Android things -->
   <project name="platform/abi/cpp" path="abi/cpp" revision="dd924f92906085b831bf1cbbc7484d3c043d613c"/>

--- a/b2g/config/gaia.json
+++ b/b2g/config/gaia.json
@@ -1,4 +1,4 @@
 {
-    "revision": "a43f6c119d80637dd3e36975e8f38b7f19b5c95c", 
+    "revision": "98abf6bda1c12b45389ec6bc2acd3e3e901e3163", 
     "repo_path": "/integration/gaia-central"
 }

--- a/b2g/config/hamachi/sources.xml
+++ b/b2g/config/hamachi/sources.xml
@@ -6,17 +6,17 @@
   <remote fetch="https://git.mozilla.org/releases" name="mozillaorg"/>
   <remote fetch="https://git.mozilla.org/external/apitrace" name="apitrace"/>
   <default remote="caf" revision="b2g/ics_strawberry" sync-j="4"/>
   <!-- Gonk specific things and forks -->
   <project name="platform_build" path="build" remote="b2g" revision="59605a7c026ff06cc1613af3938579b1dddc6cfe">
     <copyfile dest="Makefile" src="core/root.mk"/>
   </project>
   <project name="fake-dalvik" path="dalvik" remote="b2g" revision="ca1f327d5acc198bb4be62fa51db2c039032c9ce"/>
-  <project name="gaia.git" path="gaia" remote="mozillaorg" revision="e0b7c709ddc21c407ee3360d3203e9eb84535b66"/>
+  <project name="gaia.git" path="gaia" remote="mozillaorg" revision="8d18b1e2fd06c84a879f99f6e8ca1f104eeacb13"/>
   <project name="gonk-misc" path="gonk-misc" remote="b2g" revision="e9b6626eddbc85873eaa2a9174a9bd5101e5c05f"/>
   <project name="rilproxy" path="rilproxy" remote="b2g" revision="827214fcf38d6569aeb5c6d6f31cb296d1f09272"/>
   <project name="librecovery" path="librecovery" remote="b2g" revision="84f2f2fce22605e17d511ff1767e54770067b5b5"/>
   <project name="moztt" path="external/moztt" remote="b2g" revision="96d2d00165f4561fbde62d1062706eab74b3a01f"/>
   <project name="apitrace" path="external/apitrace" remote="apitrace" revision="e2f73049f8d52fb06cb9b5d923c1280557aa9238"/>
   <!-- Stock Android things -->
   <project name="platform/abi/cpp" path="abi/cpp" revision="6426040f1be4a844082c9769171ce7f5341a5528"/>
   <project name="platform/bionic" path="bionic" revision="d2eb6c7b6e1bc7643c17df2d9d9bcb1704d0b9ab"/>

--- a/b2g/config/helix/sources.xml
+++ b/b2g/config/helix/sources.xml
@@ -5,17 +5,17 @@
   <remote fetch="https://git.mozilla.org/external/caf" name="caf"/>
   <remote fetch="https://git.mozilla.org/releases" name="mozillaorg"/>
   <default remote="caf" revision="b2g/ics_strawberry" sync-j="4"/>
   <!-- Gonk specific things and forks -->
   <project name="platform_build" path="build" remote="b2g" revision="59605a7c026ff06cc1613af3938579b1dddc6cfe">
     <copyfile dest="Makefile" src="core/root.mk"/>
   </project>
   <project name="fake-dalvik" path="dalvik" remote="b2g" revision="ca1f327d5acc198bb4be62fa51db2c039032c9ce"/>
-  <project name="gaia.git" path="gaia" remote="mozillaorg" revision="e0b7c709ddc21c407ee3360d3203e9eb84535b66"/>
+  <project name="gaia.git" path="gaia" remote="mozillaorg" revision="8d18b1e2fd06c84a879f99f6e8ca1f104eeacb13"/>
   <project name="gonk-misc" path="gonk-misc" remote="b2g" revision="e9b6626eddbc85873eaa2a9174a9bd5101e5c05f"/>
   <project name="rilproxy" path="rilproxy" remote="b2g" revision="827214fcf38d6569aeb5c6d6f31cb296d1f09272"/>
   <project name="librecovery" path="librecovery" remote="b2g" revision="84f2f2fce22605e17d511ff1767e54770067b5b5"/>
   <project name="moztt" path="external/moztt" remote="b2g" revision="96d2d00165f4561fbde62d1062706eab74b3a01f"/>
   <project name="gonk-patches" path="patches" remote="b2g" revision="223a2421006e8f5da33f516f6891c87cae86b0f6"/>
   <!-- Stock Android things -->
   <project name="platform/abi/cpp" path="abi/cpp" revision="6426040f1be4a844082c9769171ce7f5341a5528"/>
   <project name="platform/bionic" path="bionic" revision="d2eb6c7b6e1bc7643c17df2d9d9bcb1704d0b9ab"/>

--- a/b2g/config/inari/sources.xml
+++ b/b2g/config/inari/sources.xml
@@ -7,17 +7,17 @@
   <remote fetch="https://git.mozilla.org/releases" name="mozillaorg"/>
   <remote fetch="https://git.mozilla.org/external/apitrace" name="apitrace"/>
   <default remote="caf" revision="ics_chocolate_rb4.2" sync-j="4"/>
   <!-- Gonk specific things and forks -->
   <project name="platform_build" path="build" remote="b2g" revision="59605a7c026ff06cc1613af3938579b1dddc6cfe">
     <copyfile dest="Makefile" src="core/root.mk"/>
   </project>
   <project name="fake-dalvik" path="dalvik" remote="b2g" revision="ca1f327d5acc198bb4be62fa51db2c039032c9ce"/>
-  <project name="gaia.git" path="gaia" remote="mozillaorg" revision="e0b7c709ddc21c407ee3360d3203e9eb84535b66"/>
+  <project name="gaia.git" path="gaia" remote="mozillaorg" revision="8d18b1e2fd06c84a879f99f6e8ca1f104eeacb13"/>
   <project name="gonk-misc" path="gonk-misc" remote="b2g" revision="e9b6626eddbc85873eaa2a9174a9bd5101e5c05f"/>
   <project name="rilproxy" path="rilproxy" remote="b2g" revision="827214fcf38d6569aeb5c6d6f31cb296d1f09272"/>
   <project name="librecovery" path="librecovery" remote="b2g" revision="84f2f2fce22605e17d511ff1767e54770067b5b5"/>
   <project name="moztt" path="external/moztt" remote="b2g" revision="96d2d00165f4561fbde62d1062706eab74b3a01f"/>
   <project name="apitrace" path="external/apitrace" remote="apitrace" revision="e2f73049f8d52fb06cb9b5d923c1280557aa9238"/>
   <!-- Stock Android things -->
   <project name="platform/abi/cpp" path="abi/cpp" revision="6426040f1be4a844082c9769171ce7f5341a5528"/>
   <project name="platform/bionic" path="bionic" revision="cd5dfce80bc3f0139a56b58aca633202ccaee7f8"/>

--- a/b2g/config/leo/sources.xml
+++ b/b2g/config/leo/sources.xml
@@ -6,17 +6,17 @@
   <remote fetch="https://git.mozilla.org/releases" name="mozillaorg"/>
   <remote fetch="https://git.mozilla.org/external/apitrace" name="apitrace"/>
   <default remote="caf" revision="b2g/ics_strawberry" sync-j="4"/>
   <!-- Gonk specific things and forks -->
   <project name="platform_build" path="build" remote="b2g" revision="59605a7c026ff06cc1613af3938579b1dddc6cfe">
     <copyfile dest="Makefile" src="core/root.mk"/>
   </project>
   <project name="fake-dalvik" path="dalvik" remote="b2g" revision="ca1f327d5acc198bb4be62fa51db2c039032c9ce"/>
-  <project name="gaia.git" path="gaia" remote="mozillaorg" revision="e0b7c709ddc21c407ee3360d3203e9eb84535b66"/>
+  <project name="gaia.git" path="gaia" remote="mozillaorg" revision="8d18b1e2fd06c84a879f99f6e8ca1f104eeacb13"/>
   <project name="gonk-misc" path="gonk-misc" remote="b2g" revision="e9b6626eddbc85873eaa2a9174a9bd5101e5c05f"/>
   <project name="rilproxy" path="rilproxy" remote="b2g" revision="827214fcf38d6569aeb5c6d6f31cb296d1f09272"/>
   <project name="librecovery" path="librecovery" remote="b2g" revision="84f2f2fce22605e17d511ff1767e54770067b5b5"/>
   <project name="moztt" path="external/moztt" remote="b2g" revision="96d2d00165f4561fbde62d1062706eab74b3a01f"/>
   <project name="apitrace" path="external/apitrace" remote="apitrace" revision="e2f73049f8d52fb06cb9b5d923c1280557aa9238"/>
   <project name="gonk-patches" path="patches" remote="b2g" revision="223a2421006e8f5da33f516f6891c87cae86b0f6"/>
   <!-- Stock Android things -->
   <project name="platform/abi/cpp" path="abi/cpp" revision="6426040f1be4a844082c9769171ce7f5341a5528"/>

--- a/b2g/config/mako/sources.xml
+++ b/b2g/config/mako/sources.xml
@@ -6,17 +6,17 @@
   <remote fetch="https://git.mozilla.org/external/caf" name="caf"/>
   <remote fetch="https://git.mozilla.org/releases" name="mozillaorg"/>
   <!-- B2G specific things. -->
   <project name="platform_build" path="build" remote="b2g" revision="fce1a137746dbd354bca1918f02f96d51c40bad2">
     <copyfile dest="Makefile" src="core/root.mk"/>
   </project>
   <project name="rilproxy" path="rilproxy" remote="b2g" revision="827214fcf38d6569aeb5c6d6f31cb296d1f09272"/>
   <project name="fake-libdvm" path="dalvik" remote="b2g" revision="d50ae982b19f42f0b66d08b9eb306be81687869f"/>
-  <project name="gaia" path="gaia" remote="mozillaorg" revision="e0b7c709ddc21c407ee3360d3203e9eb84535b66"/>
+  <project name="gaia" path="gaia" remote="mozillaorg" revision="8d18b1e2fd06c84a879f99f6e8ca1f104eeacb13"/>
   <project name="gonk-misc" path="gonk-misc" remote="b2g" revision="e9b6626eddbc85873eaa2a9174a9bd5101e5c05f"/>
   <project name="moztt" path="external/moztt" remote="b2g" revision="96d2d00165f4561fbde62d1062706eab74b3a01f"/>
   <project name="apitrace" path="external/apitrace" remote="apitrace" revision="e2f73049f8d52fb06cb9b5d923c1280557aa9238"/>
   <project name="valgrind" path="external/valgrind" remote="b2g" revision="905bfa3548eb75cf1792d0d8412b92113bbd4318"/>
   <project name="vex" path="external/VEX" remote="b2g" revision="c3d7efc45414f1b44cd9c479bb2758c91c4707c0"/>
   <!-- Stock Android things -->
   <project groups="linux" name="platform/prebuilts/clang/linux-x86/3.1" path="prebuilts/clang/linux-x86/3.1" revision="5c45f43419d5582949284eee9cef0c43d866e03b"/>
   <project groups="linux" name="platform/prebuilts/clang/linux-x86/3.2" path="prebuilts/clang/linux-x86/3.2" revision="3748b4168e7bd8d46457d4b6786003bc6a5223ce"/>

--- a/b2g/config/wasabi/sources.xml
+++ b/b2g/config/wasabi/sources.xml
@@ -6,17 +6,17 @@
   <remote fetch="https://git.mozilla.org/releases" name="mozillaorg"/>
   <remote fetch="https://git.mozilla.org/external/apitrace" name="apitrace"/>
   <default remote="caf" revision="ics_chocolate_rb4.2" sync-j="4"/>
   <!-- Gonk specific things and forks -->
   <project name="platform_build" path="build" remote="b2g" revision="59605a7c026ff06cc1613af3938579b1dddc6cfe">
     <copyfile dest="Makefile" src="core/root.mk"/>
   </project>
   <project name="fake-dalvik" path="dalvik" remote="b2g" revision="ca1f327d5acc198bb4be62fa51db2c039032c9ce"/>
-  <project name="gaia.git" path="gaia" remote="mozillaorg" revision="e0b7c709ddc21c407ee3360d3203e9eb84535b66"/>
+  <project name="gaia.git" path="gaia" remote="mozillaorg" revision="8d18b1e2fd06c84a879f99f6e8ca1f104eeacb13"/>
   <project name="gonk-misc" path="gonk-misc" remote="b2g" revision="e9b6626eddbc85873eaa2a9174a9bd5101e5c05f"/>
   <project name="rilproxy" path="rilproxy" remote="b2g" revision="827214fcf38d6569aeb5c6d6f31cb296d1f09272"/>
   <project name="librecovery" path="librecovery" remote="b2g" revision="84f2f2fce22605e17d511ff1767e54770067b5b5"/>
   <project name="moztt" path="external/moztt" remote="b2g" revision="96d2d00165f4561fbde62d1062706eab74b3a01f"/>
   <project name="apitrace" path="external/apitrace" remote="apitrace" revision="e2f73049f8d52fb06cb9b5d923c1280557aa9238"/>
   <project name="gonk-patches" path="patches" remote="b2g" revision="223a2421006e8f5da33f516f6891c87cae86b0f6"/>
   <!-- Stock Android things -->
   <project name="platform/abi/cpp" path="abi/cpp" revision="6426040f1be4a844082c9769171ce7f5341a5528"/>

--- a/browser/base/content/browser-places.js
+++ b/browser/base/content/browser-places.js
@@ -994,17 +994,17 @@ let BookmarkingUI = {
     if (event.target != event.currentTarget)
       return;
 
     let widget = CustomizableUI.getWidget("bookmarks-menu-button")
                                .forWindow(window);
     if (widget.overflowed) {
       // Don't open a popup in the overflow popup, rather just open the Library.
       event.preventDefault();
-      widget.node.removeAttribute("noautoclose");
+      widget.node.removeAttribute("closemenu");
       PlacesCommandHook.showPlacesOrganizer("BookmarksMenu");
       return;
     }
 
     if (!this._popupNeedsUpdate)
       return;
     this._popupNeedsUpdate = false;
 
@@ -1167,28 +1167,28 @@ let BookmarkingUI = {
 
     // Handle special case when the button is in the panel.
     let widgetGroup = CustomizableUI.getWidget("bookmarks-menu-button");
     let widget = widgetGroup.forWindow(window);
     if (widgetGroup.areaType == CustomizableUI.TYPE_MENU_PANEL) {
       let view = document.getElementById("PanelUI-bookmarks");
       view.addEventListener("ViewShowing", this.onPanelMenuViewShowing);
       view.addEventListener("ViewHiding", this.onPanelMenuViewHiding);
-      widget.node.setAttribute("noautoclose", "true");
+      widget.node.setAttribute("closemenu", "none");
       PanelUI.showSubView("PanelUI-bookmarks", widget.node,
                           CustomizableUI.AREA_PANEL);
       return;
     }
     else if (widget.overflowed) {
       // Allow to close the panel if the page is already bookmarked, cause
       // we are going to open the edit bookmark panel.
       if (this._itemIds.length > 0)
-        widget.node.removeAttribute("noautoclose");
+        widget.node.removeAttribute("closemenu");
       else
-        widget.node.setAttribute("noautoclose", "true");
+        widget.node.setAttribute("closemenu", "none");
     }
 
     // Ignore clicks on the star if we are updating its state.
     if (!this._pendingStmt) {
       PlacesCommandHook.bookmarkCurrentPage(this._itemIds.length > 0);
     }
   },
 

--- a/browser/base/content/browser-social.js
+++ b/browser/base/content/browser-social.js
@@ -1166,17 +1166,17 @@ SocialStatus = {
     // if we're a slice in the hamburger, use that panel instead
     let widgetGroup = CustomizableUI.getWidget(aToolbarButton.getAttribute("id"));
     let widget = widgetGroup.forWindow(window);
     let panel, showingEvent, hidingEvent;
     let inMenuPanel = widgetGroup.areaType == CustomizableUI.TYPE_MENU_PANEL;
     if (inMenuPanel) {
       panel = document.getElementById("PanelUI-socialapi");
       this._attachNotificatonPanel(panel, aToolbarButton, provider);
-      widget.node.setAttribute("noautoclose", "true");
+      widget.node.setAttribute("closemenu", "none");
       showingEvent = "ViewShowing";
       hidingEvent = "ViewHiding";
     } else {
       panel = document.getElementById("social-notification-panel");
       this._attachNotificatonPanel(panel, aToolbarButton, provider);
       showingEvent = "popupshown";
       hidingEvent = "popuphidden";
     }

--- a/browser/base/content/socialmarks.xml
+++ b/browser/base/content/socialmarks.xml
@@ -18,17 +18,17 @@
       <field name="inMenuPanel">false</field>
 
       <property name="panel">
         <getter>
           let widgetGroup = CustomizableUI.getWidget(this.getAttribute("id"));
           let widget = widgetGroup.forWindow(window);
           this.inMenuPanel = widgetGroup.areaType == CustomizableUI.TYPE_MENU_PANEL;
           if (this.inMenuPanel) {
-            widget.node.setAttribute("noautoclose", "true");
+            widget.node.setAttribute("closemenu", "none");
             return document.getElementById("PanelUI-socialapi");
           }
           return document.getAnonymousElementByAttribute(this, "anonid", "panel");
         </getter>
       </property>
 
       <property name="content">
         <getter><![CDATA[

--- a/browser/components/customizableui/content/customizeMode.inc.xul
+++ b/browser/components/customizableui/content/customizeMode.inc.xul
@@ -2,18 +2,27 @@
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
 <hbox id="customization-container" flex="1" hidden="true">
   <vbox flex="1" id="customization-palette-container">
     <label id="customization-header">
       &customizeMode.menuAndToolbars.header;
     </label>
+    <hbox id="customization-empty" hidden="true">
+      <label>&customizeMode.menuAndToolbars.empty;</label>
+      <label onclick="BrowserOpenAddonsMgr('addons://discovery/');"
+             onkeypress="BrowserOpenAddonsMgr('addons://discovery/');"
+             id="customization-more-tools"
+             class="text-link">
+        &customizeMode.menuAndToolbars.emptyLink;
+      </label>
+    </hbox>
     <vbox id="customization-palette" flex="1"/>
-    <spacer flex="1"/>
+    <spacer id="customization-spacer" flex="1"/>
     <hbox>
       <button id="customization-toolbar-visibility-button" label="&customizeMode.toolbars;" class="customizationmode-button" type="menu">
         <menupopup id="customization-toolbar-menu" onpopupshowing="onViewToolbarsPopupShowing(event)"/>
       </button>
       <spacer flex="1"/>
       <button id="customization-reset-button" oncommand="gCustomizeMode.reset();" label="&customizeMode.restoreDefaults;" class="customizationmode-button"/>
     </hbox>
   </vbox>

--- a/browser/components/customizableui/content/panelUI.js
+++ b/browser/components/customizableui/content/panelUI.js
@@ -325,19 +325,25 @@ const PanelUI = {
     }
   },
 
   /**
    * This function can be used as a command event listener for subviews
    * so that the panel knows if and when to close itself.
    */
   onCommandHandler: function(aEvent) {
-    if (!aEvent.originalTarget.hasAttribute("noautoclose")) {
-      PanelUI.hide();
+    let closemenu = aEvent.originalTarget.getAttribute("closemenu");
+    if (closemenu == "none") {
+      return;
     }
+    if (closemenu == "single") {
+      this.showMainView();
+      return;
+    }
+    this.hide();
   },
 
   /**
    * Open a dialog window that allow the user to customize listed character sets.
    */
   onCharsetCustomizeCommand: function() {
     this.hide();
     window.openDialog("chrome://global/content/customizeCharset.xul",

--- a/browser/components/customizableui/src/CustomizableUI.jsm
+++ b/browser/components/customizableui/src/CustomizableUI.jsm
@@ -1225,30 +1225,31 @@ let CustomizableUIInternal = {
   maybeAutoHidePanel: function(aEvent) {
     if (aEvent.type == "keypress") {
       if (aEvent.keyCode != aEvent.DOM_VK_ENTER &&
           aEvent.keyCode != aEvent.DOM_VK_RETURN) {
         return;
       }
       // If the user hit enter/return, we don't check preventDefault - it makes sense
       // that this was prevented, but we probably still want to close the panel.
-      // If consumers don't want this to happen, they should specify noautoclose.
+      // If consumers don't want this to happen, they should specify the closemenu
+      // attribute.
 
     } else if (aEvent.type != "command") { // mouse events:
       if (aEvent.defaultPrevented || aEvent.button != 0) {
         return;
       }
       let isInteractive = this._isOnInteractiveElement(aEvent);
       LOG("maybeAutoHidePanel: interactive ? " + isInteractive);
       if (isInteractive) {
         return;
       }
     }
 
-    if (aEvent.target.getAttribute("noautoclose") == "true" ||
+    if (aEvent.target.getAttribute("closemenu") == "none" ||
         aEvent.target.getAttribute("widget-type") == "view") {
       return;
     }
 
     // If we get here, we can actually hide the popup:
     this.hidePanelForNode(aEvent.target);
   },
 

--- a/browser/components/customizableui/src/CustomizableWidgets.jsm
+++ b/browser/components/customizableui/src/CustomizableWidgets.jsm
@@ -39,22 +39,22 @@ function setAttributes(aNode, aAttrs) {
     } else {
       if (name == "label" || name == "tooltiptext")
         value = CustomizableUI.getLocalizedProperty({id: aAttrs.id}, name);
       aNode.setAttribute(name, value);
     }
   }
 }
 
-function updateCombinedWidgetStyle(aNode, aArea, aModifyAutoclose) {
+function updateCombinedWidgetStyle(aNode, aArea, aModifyCloseMenu) {
   let inPanel = (aArea == CustomizableUI.AREA_PANEL);
   let cls = inPanel ? "panel-combined-button" : "toolbarbutton-1";
   let attrs = {class: cls};
-  if (aModifyAutoclose) {
-    attrs.noautoclose = inPanel ? true : null;
+  if (aModifyCloseMenu) {
+    attrs.closemenu = inPanel ? "none" : null;
   }
   for (let i = 0, l = aNode.childNodes.length; i < l; ++i) {
     if (aNode.childNodes[i].localName == "separator")
       continue;
     setAttributes(aNode.childNodes[i], attrs);
   }
 }
 
@@ -306,38 +306,38 @@ const CustomizableWidgets = [{
     id: "zoom-controls",
     type: "custom",
     defaultArea: CustomizableUI.AREA_PANEL,
     onBuild: function(aDocument) {
       const kPanelId = "PanelUI-popup";
       let areaType = CustomizableUI.getAreaType(this.currentArea);
       let inPanel = areaType == CustomizableUI.TYPE_MENU_PANEL;
       let inToolbar = areaType == CustomizableUI.TYPE_TOOLBAR;
-      let noautoclose = inPanel ? "true" : null;
+      let closeMenu = inPanel ? "none" : null;
       let cls = inPanel ? "panel-combined-button" : "toolbarbutton-1";
 
       if (!this.currentArea)
         cls = null;
 
       let buttons = [{
         id: "zoom-out-button",
-        noautoclose: noautoclose,
+        closemenu: closeMenu,
         command: "cmd_fullZoomReduce",
         class: cls,
         label: true,
         tooltiptext: true
       }, {
         id: "zoom-reset-button",
-        noautoclose: noautoclose,
+        closemenu: closeMenu,
         command: "cmd_fullZoomReset",
         class: cls,
         tooltiptext: true
       }, {
         id: "zoom-in-button",
-        noautoclose: noautoclose,
+        closemenu: closeMenu,
         command: "cmd_fullZoomEnlarge",
         class: cls,
         label: true,
         tooltiptext: true
       }];
 
       let node = aDocument.createElementNS(kNSXUL, "toolbaritem");
       node.setAttribute("id", "zoom-controls");

--- a/browser/components/customizableui/src/CustomizeMode.jsm
+++ b/browser/components/customizableui/src/CustomizeMode.jsm
@@ -43,16 +43,18 @@ function CustomizeMode(aWindow) {
   this.document = aWindow.document;
   this.browser = aWindow.gBrowser;
 
   // There are two palettes - there's the palette that can be overlayed with
   // toolbar items in browser.xul. This is invisible, and never seen by the
   // user. Then there's the visible palette, which gets populated and displayed
   // to the user when in customizing mode.
   this.visiblePalette = this.document.getElementById(kPaletteId);
+  this.paletteEmptyNotice = this.document.getElementById("customization-empty");
+  this.paletteSpacer = this.document.getElementById("customization-spacer");
 };
 
 CustomizeMode.prototype = {
   _changed: false,
   _transitioning: false,
   window: null,
   document: null,
   // areas is used to cache the customizable areas when in customization mode.
@@ -223,16 +225,18 @@ CustomizeMode.prototype = {
 
       CustomizableUI.addListener(this);
       window.PanelUI.endBatchUpdate();
       this._customizing = true;
       this._transitioning = false;
 
       // Show the palette now that the transition has finished.
       this.visiblePalette.hidden = false;
+      this.paletteSpacer.hidden = true;
+      this._updateEmptyPaletteNotice();
 
       this._handler.isEnteringCustomizeMode = false;
       this.dispatchToolboxEvent("customizationready");
       if (!this._wantToBeInCustomizeMode) {
         this.exit();
       }
     }.bind(this)).then(null, function(e) {
       ERROR(e);
@@ -268,17 +272,19 @@ CustomizeMode.prototype = {
 
     this._removePanelCustomizationPlaceholders();
 
     let window = this.window;
     let document = this.document;
     let documentElement = document.documentElement;
 
     // Hide the palette before starting the transition for increased perf.
+    this.paletteSpacer.hidden = false;
     this.visiblePalette.hidden = true;
+    this.paletteEmptyNotice.hidden = true;
 
     this._transitioning = true;
 
     Task.spawn(function() {
       yield this.depopulatePalette();
 
       yield this._doTransition(false);
 
@@ -908,19 +914,25 @@ CustomizeMode.prototype = {
         this.visiblePalette.appendChild(this.makePaletteItem(widget, "palette"));
       }
     }
   },
 
   _onUIChange: function() {
     this._changed = true;
     this._updateResetButton();
+    this._updateEmptyPaletteNotice();
     this.dispatchToolboxEvent("customizationchange");
   },
 
+  _updateEmptyPaletteNotice: function() {
+    let paletteItems = this.visiblePalette.getElementsByTagName("toolbarpaletteitem");
+    this.paletteEmptyNotice.hidden = !!paletteItems.length;
+  },
+
   _updateResetButton: function() {
     let btn = this.document.getElementById("customization-reset-button");
     btn.disabled = CustomizableUI.inDefaultState;
   },
 
   handleEvent: function(aEvent) {
     switch(aEvent.type) {
       case "toolbarvisibilitychange":

--- a/browser/components/customizableui/test/browser.ini
+++ b/browser/components/customizableui/test/browser.ini
@@ -32,16 +32,17 @@ skip-if = os == "mac"
 # Because of the specific widths, this test is fragile and has been disabled.
 # NB: it was designed for mac only, but started randomly failing there.
 skip-if = true
 
 [browser_914863_disabled_help_quit_buttons.js]
 [browser_918049_skipintoolbarset_dnd.js]
 [browser_923857_customize_mode_event_wrapping_during_reset.js]
 [browser_927717_customize_drag_empty_toolbar.js]
+[browser_932928_show_notice_when_palette_empty.js]
 
 [browser_934113_menubar_removable.js]
 # Because this test is about the menubar, it can't be run on mac
 skip-if = os == "mac"
 
 [browser_946320_tabs_from_other_computers.js]
 skip-if = os == "linux"
 

new file mode 100644
--- /dev/null
+++ b/browser/components/customizableui/test/browser_932928_show_notice_when_palette_empty.js
@@ -0,0 +1,35 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+// There should be an advert to get more addons when the palette is empty.
+add_task(function() {
+  yield startCustomizing();
+  let visiblePalette = document.getElementById("customization-palette");
+  let emptyPaletteNotice = document.getElementById("customization-empty");
+  is(emptyPaletteNotice.hidden, true, "The empty palette notice should not be shown when there are items in the palette.");
+
+  while (visiblePalette.childElementCount) {
+    gCustomizeMode.addToToolbar(visiblePalette.children[0]);
+  }
+  is(visiblePalette.childElementCount, 0, "There shouldn't be any items remaining in the visible palette.");
+  is(emptyPaletteNotice.hidden, false, "The empty palette notice should be shown when there are no items in the palette.");
+
+  yield endCustomizing();
+  yield startCustomizing();
+  visiblePalette = document.getElementById("customization-palette");
+  emptyPaletteNotice = document.getElementById("customization-empty");
+  is(emptyPaletteNotice.hidden, false,
+     "The empty palette notice should be shown when there are no items in the palette and cust. mode is re-entered.");
+
+  gCustomizeMode.removeFromArea(document.getElementById("wrapper-home-button"));
+  is(emptyPaletteNotice.hidden, true,
+     "The empty palette notice should not be shown when there is at least one item in the palette.");
+});
+
+add_task(function asyncCleanup() {
+  yield endCustomizing();
+  yield resetCustomization();
+});

--- a/browser/devtools/scratchpad/test/browser_scratchpad_wrong_window_focus.js
+++ b/browser/devtools/scratchpad/test/browser_scratchpad_wrong_window_focus.js
@@ -1,13 +1,14 @@
 /* vim:set ts=2 sw=2 sts=2 et: */
 /* Any copyright is dedicated to the Public Domain.
    http://creativecommons.org/publicdomain/zero/1.0/ */
 /* Bug 661762 */
 
+
 function test()
 {
   waitForExplicitFinish();
 
   // To test for this bug we open a Scratchpad window, save its
   // reference and then open another one. This way the first window
   // loses its focus.
   //
@@ -20,32 +21,25 @@ function test()
   // is currently active (it should be the older one).
 
   gBrowser.selectedTab = gBrowser.addTab();
   gBrowser.selectedBrowser.addEventListener("load", function onLoad() {
     gBrowser.selectedBrowser.removeEventListener("load", onLoad, true);
 
     openScratchpad(function () {
       let sw = gScratchpadWindow;
+      let {devtools} = Cu.import("resource://gre/modules/devtools/Loader.jsm", {});
 
       openScratchpad(function () {
-        function onWebConsoleOpen(subj) {
-          Services.obs.removeObserver(onWebConsoleOpen,
-            "web-console-created");
-          subj.QueryInterface(Ci.nsISupportsString);
-
-          let hud = HUDService.getHudReferenceById(subj.data);
+        let target = devtools.TargetFactory.forTab(gBrowser.selectedTab);
+        gDevTools.showToolbox(target, "webconsole").then((toolbox) => {
+          let hud = toolbox.getCurrentPanel().hud;
           hud.jsterm.clearOutput(true);
-          executeSoon(testFocus.bind(null, sw, hud));
-        }
-
-        Services.obs.
-          addObserver(onWebConsoleOpen, "web-console-created", false);
-
-        HUDService.toggleWebConsole();
+          testFocus(sw, hud);
+        });
       });
     });
   }, true);
 
   content.location = "data:text/html;charset=utf8,<p>test window focus for Scratchpad.";
 }
 
 function testFocus(sw, hud) {

--- a/browser/devtools/webconsole/hudservice.js
+++ b/browser/devtools/webconsole/hudservice.js
@@ -138,34 +138,16 @@ HUD_SERVICE.prototype =
    * @returns Object
    */
   getHudReferenceById: function HS_getHudReferenceById(aId)
   {
     return this.consoles.get(aId);
   },
 
   /**
-   * Toggle the Web Console for the current tab.
-   *
-   * @return object
-   *         A promise for either the opening of the toolbox that holds the Web
-   *         Console, or a Promise for the closing of the toolbox.
-   */
-  toggleWebConsole: function HS_toggleWebConsole()
-  {
-    let window = this.currentContext();
-    let target = devtools.TargetFactory.forTab(window.gBrowser.selectedTab);
-    let toolbox = gDevTools.getToolbox(target);
-
-    return toolbox && toolbox.currentToolId == "webconsole" ?
-        toolbox.destroy() :
-        gDevTools.showToolbox(target, "webconsole");
-  },
-
-  /**
    * Find if there is a Web Console open for the current tab and return the
    * instance.
    * @return object|null
    *         The WebConsole object or null if the active tab has no open Web
    *         Console.
    */
   getOpenWebConsole: function HS_getOpenWebConsole()
   {
@@ -739,17 +721,17 @@ BrowserConsole.prototype = Heritage.exte
 
     return this._bc_destroyer.promise;
   },
 });
 
 const HUDService = new HUD_SERVICE();
 
 (() => {
-  let methods = ["openWebConsole", "openBrowserConsole", "toggleWebConsole",
+  let methods = ["openWebConsole", "openBrowserConsole",
                  "toggleBrowserConsole", "getOpenWebConsole",
                  "getBrowserConsole", "getHudByWindow", "getHudReferenceById"];
   for (let method of methods) {
     exports[method] = HUDService[method].bind(HUDService);
   }
 
   exports.consoles = HUDService.consoles;
   exports.lastFinishedRequest = HUDService.lastFinishedRequest;

--- a/browser/devtools/webconsole/test/browser.ini
+++ b/browser/devtools/webconsole/test/browser.ini
@@ -110,16 +110,17 @@ support-files =
 [browser_bug_865288_repeat_different_objects.js]
 [browser_bug_865871_variables_view_close_on_esc_key.js]
 [browser_bug_869003_inspect_cross_domain_object.js]
 [browser_bug_871156_ctrlw_close_tab.js]
 [browser_cached_messages.js]
 [browser_console.js]
 [browser_console_addonsdk_loader_exception.js]
 [browser_console_clear_on_reload.js]
+[browser_console_click_focus.js]
 [browser_console_consolejsm_output.js]
 [browser_console_dead_objects.js]
 [browser_console_error_source_click.js]
 [browser_console_filters.js]
 [browser_console_iframe_messages.js]
 [browser_console_keyboard_accessibility.js]
 [browser_console_log_inspectable_object.js]
 [browser_console_native_getters.js]

new file mode 100644
--- /dev/null
+++ b/browser/devtools/webconsole/test/browser_console_click_focus.js
@@ -0,0 +1,39 @@
+/* vim:set ts=2 sw=2 sts=2 et: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// Tests that the input field is focused when the console is opened.
+
+const TEST_URI = "http://example.com/browser/browser/devtools/webconsole/test/test-console.html";
+
+function test() {
+  addTab(TEST_URI);
+  browser.addEventListener("DOMContentLoaded", testInputFocus, false);
+}
+
+function testInputFocus() {
+  browser.removeEventListener("DOMContentLoaded", testInputFocus, false);
+
+  openConsole().then((hud) => {
+    let inputNode = hud.jsterm.inputNode;
+    ok(inputNode.getAttribute("focused"), "input node is focused");
+
+    let lostFocus = () => {
+      inputNode.removeEventListener("blur", lostFocus);
+      info("input node lost focus");
+    }
+
+   	inputNode.addEventListener("blur", lostFocus);
+
+   	browser.ownerDocument.getElementById("urlbar").click();
+
+  	ok(!inputNode.getAttribute("focused"), "input node is not focused");
+
+   	hud.outputNode.click();
+
+   	ok(inputNode.getAttribute("focused"), "input node is focused");
+
+      finishTest();
+  });
+}

--- a/browser/devtools/webconsole/webconsole.js
+++ b/browser/devtools/webconsole/webconsole.js
@@ -564,16 +564,29 @@ WebConsoleFrame.prototype = {
     this.jsterm.init();
     this.jsterm.inputNode.focus();
 
     let toolbox = gDevTools.getToolbox(this.owner.target);
     if (toolbox) {
       toolbox.on("webconsole-selected", this._onPanelSelected);
     }
 
+    /*
+     * Focus input line whenever the output area is clicked.
+     * Only focus when the target node (or parent, as in source links) is
+     * not an anchor.
+     */
+    this.outputNode.addEventListener("click", (e) => {
+      if ((e.button == 0) &&
+          (e.target.nodeName.toLowerCase() != "a") &&
+          (e.target.parentNode.nodeName.toLowerCase() != "a")) {
+        this.jsterm.inputNode.focus();
+      }
+    });
+
     // Toggle the timestamp on preference change
     gDevTools.on("pref-changed", this._onToolboxPrefChanged);
     this._onToolboxPrefChanged("pref-changed", {
       pref: PREF_MESSAGE_TIMESTAMP,
       newValue: Services.prefs.getBoolPref(PREF_MESSAGE_TIMESTAMP),
     });
   },
 

--- a/browser/locales/en-US/chrome/browser/browser.dtd
+++ b/browser/locales/en-US/chrome/browser/browser.dtd
@@ -672,16 +672,18 @@ just addresses the organization to follo
 <!ENTITY social.learnMore.accesskey "l">
 <!ENTITY social.closeNotificationItem.label "Not Now">
 
 
 
 <!ENTITY customizeMode.tabTitle "Customize &brandShortName;">
 <!ENTITY customizeMode.menuAndToolbars.label "Menu and toolbars">
 <!ENTITY customizeMode.menuAndToolbars.header "More Tools to Add to the Menu and Toolbar">
+<!ENTITY customizeMode.menuAndToolbars.empty "Want more tools?">
+<!ENTITY customizeMode.menuAndToolbars.emptyLink "Choose from thousands of add-ons">
 <!ENTITY customizeMode.restoreDefaults "Restore Defaults">
 <!ENTITY customizeMode.toolbars "Show / Hide Toolbars">
 
 <!ENTITY social.chatBar.commandkey "c">
 <!ENTITY social.chatBar.label "Focus chats">
 <!ENTITY social.chatBar.accesskey "c">
 
 <!ENTITY social.markpageMenu.accesskey "P">

--- a/browser/metro/base/content/Util.js
+++ b/browser/metro/base/content/Util.js
@@ -78,40 +78,54 @@ let Util = {
   },
 
   isTextInput: function isTextInput(aElement) {
     return ((aElement instanceof Ci.nsIDOMHTMLInputElement &&
              aElement.mozIsTextField(false)) ||
             aElement instanceof Ci.nsIDOMHTMLTextAreaElement);
   },
 
+  /**
+   * Checks whether aElement's content can be edited either if it(or any of its
+   * parents) has "contenteditable" attribute set to "true" or aElement's
+   * ownerDocument is in design mode.
+   */
   isEditableContent: function isEditableContent(aElement) {
-    if (!aElement)
-      return false;
-    if (aElement.isContentEditable || aElement.designMode == "on")
-      return true;
-    return false;
+    return !!aElement && (aElement.isContentEditable ||
+                          this.isOwnerDocumentInDesignMode(aElement));
+
   },
 
   isEditable: function isEditable(aElement) {
-    if (!aElement)
+    if (!aElement) {
       return false;
-    if (this.isTextInput(aElement) || this.isEditableContent(aElement))
+    }
+
+    if (this.isTextInput(aElement) || this.isEditableContent(aElement)) {
       return true;
+    }
 
     // If a body element is editable and the body is the child of an
     // iframe or div we can assume this is an advanced HTML editor
     if ((aElement instanceof Ci.nsIDOMHTMLIFrameElement ||
          aElement instanceof Ci.nsIDOMHTMLDivElement) &&
         aElement.contentDocument &&
         this.isEditableContent(aElement.contentDocument.body)) {
       return true;
     }
 
-    return aElement.ownerDocument && aElement.ownerDocument.designMode == "on";
+    return false;
+  },
+
+  /**
+   * Checks whether aElement's owner document has design mode turned on.
+   */
+  isOwnerDocumentInDesignMode: function(aElement) {
+    return !!aElement && !!aElement.ownerDocument &&
+           aElement.ownerDocument.designMode == "on";
   },
 
   isMultilineInput: function isMultilineInput(aElement) {
     return (aElement instanceof Ci.nsIDOMHTMLTextAreaElement);
   },
 
   isLink: function isLink(aElement) {
     return ((aElement instanceof Ci.nsIDOMHTMLAnchorElement && aElement.href) ||

--- a/browser/metro/base/content/contenthandlers/ContextMenuHandler.js
+++ b/browser/metro/base/content/contenthandlers/ContextMenuHandler.js
@@ -100,33 +100,35 @@ var ContextMenuHandler = {
   /******************************************************
    * ContextCommand handlers
    */
 
   _onSelectAll: function _onSelectAll() {
     if (Util.isTextInput(this._target)) {
       // select all text in the input control
       this._target.select();
+    } else if (Util.isEditableContent(this._target)) {
+      this._target.ownerDocument.execCommand("selectAll", false);
     } else {
       // select the entire document
       content.getSelection().selectAllChildren(content.document);
     }
     this.reset();
   },
 
   _onPaste: function _onPaste() {
     // paste text if this is an input control
     if (Util.isTextInput(this._target)) {
       let edit = this._target.QueryInterface(Ci.nsIDOMNSEditableElement);
       if (edit) {
         edit.editor.paste(Ci.nsIClipboard.kGlobalClipboard);
       } else {
         Util.dumpLn("error: target element does not support nsIDOMNSEditableElement");
       }
-    } else if (this._target.isContentEditable) {
+    } else if (Util.isEditableContent(this._target)) {
       try {
         this._target.ownerDocument.execCommand("paste",
                                                false,
                                                Ci.nsIClipboard.kGlobalClipboard);
       } catch (ex) {
         dump("ContextMenuHandler: exception pasting into contentEditable: " + ex.message + "\n");
       }
     }
@@ -140,17 +142,17 @@ var ContextMenuHandler = {
   _onCut: function _onCut() {
     if (Util.isTextInput(this._target)) {
       let edit = this._target.QueryInterface(Ci.nsIDOMNSEditableElement);
       if (edit) {
         edit.editor.cut();
       } else {
         Util.dumpLn("error: target element does not support nsIDOMNSEditableElement");
       }
-    } else if (this._target.isContentEditable) {
+    } else if (Util.isEditableContent(this._target)) {
       try {
         this._target.ownerDocument.execCommand("cut", false);
       } catch (ex) {
         dump("ContextMenuHandler: exception cutting from contentEditable: " + ex.message + "\n");
       }
     }
     this.reset();
   },
@@ -254,17 +256,19 @@ var ContextMenuHandler = {
           linkUrl = state.linkURL;
           state.linkTitle = popupNode.textContent || popupNode.title;
           state.linkProtocol = this._getProtocol(this._getURI(state.linkURL));
           // mark as text so we can pickup on selection below
           isText = true;
           break;
         }
         // is the target contentEditable (not just inheriting contentEditable)
-        else if (elem.contentEditable == "true") {
+        // or the entire document in designer mode.
+        else if (elem.contentEditable == "true" ||
+                 Util.isOwnerDocumentInDesignMode(elem)) {
           this._target = elem;
           isEditableText = true;
           isText = true;
           uniqueStateTypes.add("input-text");
 
           if (elem.textContent.length) {
             uniqueStateTypes.add("selectable");
           } else {

--- a/browser/metro/base/tests/mochitest/browser_context_menu_tests.js
+++ b/browser/metro/base/tests/mochitest/browser_context_menu_tests.js
@@ -704,12 +704,90 @@ gTests.push({
 
 gTests.push({
   desc: "bug 856264 - touch - context menu should reopen on other links",
   setUp: reopenSetUp,
   tearDown: reopenTearDown,
   run: getReopenTest(sendContextMenuClickToElement, sendTap)
 });
 
+gTests.push({
+  desc: "Bug 947505 - Right-click in a designMode document should display a " +
+        "context menu",
+  run: function test() {
+    info(chromeRoot + "browser_context_menu_tests_02.html");
+    yield addTab(chromeRoot + "browser_context_menu_tests_02.html");
+
+    purgeEventQueue();
+    emptyClipboard();
+    ContextUI.dismiss();
+
+    yield waitForCondition(() => !ContextUI.navbarVisible);
+
+    let tabWindow = Browser.selectedTab.browser.contentWindow;
+    let testSpan = tabWindow.document.getElementById("text1");
+
+    // Case #1: Document isn't in design mode and nothing is selected.
+    tabWindow.document.designMode = "off";
+
+    // Simulate right mouse click to reproduce the same step as noted in the
+    // appropriate bug. It's valid for non-touch case only.
+    synthesizeNativeMouseRDown(Browser.selectedTab.browser, 10, 10);
+    synthesizeNativeMouseRUp(Browser.selectedTab.browser, 10, 10);
+
+    yield waitForCondition(() => ContextUI.navbarVisible);
+
+    ok(ContextUI.navbarVisible, "Navbar is visible on context menu action.");
+    ok(ContextUI.tabbarVisible, "Tabbar is visible on context menu action.");
+
+    ContextUI.dismiss();
+    yield waitForCondition(() => !ContextUI.navbarVisible);
+
+    // Case #2: Document isn't in design mode and text is selected.
+    tabWindow.getSelection().selectAllChildren(testSpan);
+
+    let promise = waitForEvent(tabWindow.document, "popupshown");
+    sendContextMenuClickToSelection(tabWindow);
+    yield promise;
+
+    checkContextUIMenuItemVisibility(["context-copy", "context-search"]);
+
+    promise = waitForEvent(document, "popuphidden");
+    ContextMenuUI.hide();
+    yield promise;
+
+    // Case #3: Document is in design mode and nothing is selected.
+    tabWindow.document.designMode = "on";
+    tabWindow.getSelection().removeAllRanges();
+
+    promise = waitForEvent(tabWindow.document, "popupshown");
+    sendContextMenuClickToElement(tabWindow, testSpan);
+    yield promise;
+
+    checkContextUIMenuItemVisibility(["context-select-all", "context-select"]);
+
+    promise = waitForEvent(document, "popuphidden");
+    ContextMenuUI.hide();
+    yield promise;
+
+    // Case #4: Document is in design mode and text is selected.
+    tabWindow.getSelection().selectAllChildren(testSpan);
+
+    promise = waitForEvent(tabWindow.document, "popupshown");
+    sendContextMenuClickToSelection(tabWindow);
+    yield promise;
+
+    checkContextUIMenuItemVisibility(["context-cut", "context-copy",
+                                      "context-select-all", "context-select",
+                                      "context-search"]);
+
+    promise = waitForEvent(document, "popuphidden");
+    ContextMenuUI.hide();
+    yield promise;
+
+    Browser.closeTab(Browser.selectedTab, { forceClose: true });
+  }
+});
+
 function test() {
   setDevPixelEqualToPx();
   runTests();
 }

--- a/browser/themes/osx/browser.css
+++ b/browser/themes/osx/browser.css
@@ -3955,17 +3955,17 @@ window > chatbox {
   border-bottom-left-radius: @toolbarbuttonCornerRadius@;
   border-bottom-right-radius: @toolbarbuttonCornerRadius@;
 }
 
 /* Customization mode */
 
 %include ../shared/customizableui/customizeMode.inc.css
 
-#main-window[customizing] #titlebar {
+#main-window[customize-entered] #titlebar {
   padding-top: 0;
 }
 
 #main-window:-moz-any([customize-entering],[customize-entered]) #tab-view-deck {
   padding: 0 2em 2em;
 }
 
 #main-window[customize-entered] #tab-view-deck {

--- a/dom/camera/CameraControlImpl.cpp
+++ b/dom/camera/CameraControlImpl.cpp
@@ -4,16 +4,17 @@
 
 #include "base/basictypes.h"
 #include "mozilla/Assertions.h"
 #include "DOMCameraPreview.h"
 #include "CameraRecorderProfiles.h"
 #include "CameraControlImpl.h"
 #include "CameraCommon.h"
 #include "nsGlobalWindow.h"
+#include "DeviceStorageFileDescriptor.h"
 
 using namespace mozilla;
 using namespace mozilla::dom;
 using namespace mozilla::idl;
 
 CameraControlImpl::CameraControlImpl(uint32_t aCameraId, nsIThread* aCameraThread, uint64_t aWindowId)
   : mCameraId(aCameraId)
   , mCameraThread(aCameraThread)
@@ -445,22 +446,19 @@ CameraControlImpl::TakePicture(const Cam
     cancel = true;
   }
 
   nsCOMPtr<nsIRunnable> takePictureTask = new TakePictureTask(this, cancel, aSize, aRotation, aFileFormat, aPosition, aDateTime, onSuccess, onError);
   return mCameraThread->Dispatch(takePictureTask, NS_DISPATCH_NORMAL);
 }
 
 nsresult
-CameraControlImpl::StartRecording(CameraStartRecordingOptions* aOptions, nsIFile* aFolder, const nsAString& aFilename, nsICameraStartRecordingCallback* onSuccess, nsICameraErrorCallback* onError)
+CameraControlImpl::StartRecording(CameraStartRecordingOptions* aOptions, DeviceStorageFileDescriptor* aFileDescriptor, nsICameraStartRecordingCallback* onSuccess, nsICameraErrorCallback* onError)
 {
-  nsCOMPtr<nsIFile> clone;
-  aFolder->Clone(getter_AddRefs(clone));
-
-  nsCOMPtr<nsIRunnable> startRecordingTask = new StartRecordingTask(this, *aOptions, clone, aFilename, onSuccess, onError, mWindowId);
+  nsCOMPtr<nsIRunnable> startRecordingTask = new StartRecordingTask(this, *aOptions, aFileDescriptor, onSuccess, onError, mWindowId);
   return mCameraThread->Dispatch(startRecordingTask, NS_DISPATCH_NORMAL);
 }
 
 nsresult
 CameraControlImpl::StopRecording()
 {
   nsCOMPtr<nsIRunnable> stopRecordingTask = new StopRecordingTask(this);
   return mCameraThread->Dispatch(stopRecordingTask, NS_DISPATCH_NORMAL);

--- a/dom/camera/CameraControlImpl.h
+++ b/dom/camera/CameraControlImpl.h
@@ -9,16 +9,20 @@
 #include "nsDOMFile.h"
 #include "nsProxyRelease.h"
 #include "DictionaryHelpers.h"
 #include "nsIDOMDeviceStorage.h"
 #include "DOMCameraManager.h"
 #include "DOMCameraPreview.h"
 #include "ICameraControl.h"
 #include "CameraCommon.h"
+#include "DeviceStorage.h"
+#include "DeviceStorageFileDescriptor.h"
+
+class DeviceStorageFileDescriptor;
 
 namespace mozilla {
 
 class GetPreviewStreamTask;
 class StartPreviewTask;
 class StopPreviewTask;
 class AutoFocusTask;
 class TakePictureTask;
@@ -49,17 +53,17 @@ class CameraControlImpl : public ICamera
 public:
   CameraControlImpl(uint32_t aCameraId, nsIThread* aCameraThread, uint64_t aWindowId);
 
   nsresult GetPreviewStream(idl::CameraSize aSize, nsICameraPreviewStreamCallback* onSuccess, nsICameraErrorCallback* onError);
   nsresult StartPreview(DOMCameraPreview* aDOMPreview);
   void StopPreview();
   nsresult AutoFocus(nsICameraAutoFocusCallback* onSuccess, nsICameraErrorCallback* onError);
   nsresult TakePicture(const idl::CameraSize& aSize, int32_t aRotation, const nsAString& aFileFormat, idl::CameraPosition aPosition, uint64_t aDateTime, nsICameraTakePictureCallback* onSuccess, nsICameraErrorCallback* onError);
-  nsresult StartRecording(idl::CameraStartRecordingOptions* aOptions, nsIFile* aFolder, const nsAString& aFilename, nsICameraStartRecordingCallback* onSuccess, nsICameraErrorCallback* onError);
+  nsresult StartRecording(idl::CameraStartRecordingOptions* aOptions, DeviceStorageFileDescriptor *aDSFileDescriptor, nsICameraStartRecordingCallback* onSuccess, nsICameraErrorCallback* onError);
   nsresult StopRecording();
   nsresult GetPreviewStreamVideoMode(idl::CameraRecorderOptions* aOptions, nsICameraPreviewStreamCallback* onSuccess, nsICameraErrorCallback* onError);
   nsresult ReleaseHardware(nsICameraReleaseCallback* onSuccess, nsICameraErrorCallback* onError);
 
   nsresult Set(uint32_t aKey, const nsAString& aValue);
   nsresult Get(uint32_t aKey, nsAString& aValue);
   nsresult Set(uint32_t aKey, double aValue);
   nsresult Get(uint32_t aKey, double* aValue);
@@ -447,21 +451,25 @@ protected:
   nsMainThreadPtrHandle<nsICameraStartRecordingCallback> mOnSuccessCb;
   uint64_t mWindowId;
 };
 
 // Start video recording.
 class StartRecordingTask : public nsRunnable
 {
 public:
-  StartRecordingTask(CameraControlImpl* aCameraControl, idl::CameraStartRecordingOptions aOptions, nsIFile* aFolder, const nsAString& aFilename, nsICameraStartRecordingCallback* onSuccess, nsICameraErrorCallback* onError, uint64_t aWindowId)
+  StartRecordingTask(CameraControlImpl* aCameraControl,
+                     idl::CameraStartRecordingOptions aOptions,
+                     DeviceStorageFileDescriptor *aDSFileDescriptor,
+                     nsICameraStartRecordingCallback* onSuccess,
+                     nsICameraErrorCallback* onError,
+                     uint64_t aWindowId)
     : mCameraControl(aCameraControl)
     , mOptions(aOptions)
-    , mFolder(aFolder)
-    , mFilename(aFilename)
+    , mDSFileDescriptor(aDSFileDescriptor)
     , mOnSuccessCb(new nsMainThreadPtrHolder<nsICameraStartRecordingCallback>(onSuccess))
     , mOnErrorCb(new nsMainThreadPtrHolder<nsICameraErrorCallback>(onError))
     , mWindowId(aWindowId)
   {
     DOM_CAMERA_LOGT("%s:%d : this=%p\n", __func__, __LINE__, this);
   }
 
   virtual ~StartRecordingTask()
@@ -486,18 +494,17 @@ public:
     if (NS_FAILED(rv)) {
       DOM_CAMERA_LOGE("Failed to dispatch start recording result to main thread (%d)!", rv);
     }
     return rv;
   }
 
   nsRefPtr<CameraControlImpl> mCameraControl;
   idl::CameraStartRecordingOptions mOptions;
-  nsCOMPtr<nsIFile> mFolder;
-  nsString mFilename;
+  nsRefPtr<DeviceStorageFileDescriptor> mDSFileDescriptor;
   nsMainThreadPtrHandle<nsICameraStartRecordingCallback> mOnSuccessCb;
   nsMainThreadPtrHandle<nsICameraErrorCallback> mOnErrorCb;
   uint64_t mWindowId;
 };
 
 // Stop video recording.
 class StopRecordingTask : public nsRunnable
 {

--- a/dom/camera/DOMCameraControl.cpp
+++ b/dom/camera/DOMCameraControl.cpp
@@ -3,16 +3,17 @@
  * You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #include "base/basictypes.h"
 #include "nsCOMPtr.h"
 #include "nsDOMClassInfo.h"
 #include "nsHashPropertyBag.h"
 #include "nsThread.h"
 #include "DeviceStorage.h"
+#include "DeviceStorageFileDescriptor.h"
 #include "mozilla/dom/CameraControlBinding.h"
 #include "mozilla/dom/TabChild.h"
 #include "mozilla/MediaManager.h"
 #include "mozilla/Services.h"
 #include "mozilla/unused.h"
 #include "nsIAppsService.h"
 #include "nsIObserverService.h"
 #include "nsIDOMDeviceStorage.h"
@@ -344,23 +345,22 @@ nsDOMCameraControl::StartRecording(JSCon
                                    JS::Handle<JS::Value> aOptions,
                                    nsDOMDeviceStorage& storageArea,
                                    const nsAString& filename,
                                    nsICameraStartRecordingCallback* onSuccess,
                                    const Optional<nsICameraErrorCallback*>& onError,
                                    ErrorResult& aRv)
 {
   MOZ_ASSERT(onSuccess, "no onSuccess handler passed");
-  mozilla::idl::CameraStartRecordingOptions options;
 
   // Default values, until the dictionary parser can handle them.
-  options.rotation = 0;
-  options.maxFileSizeBytes = 0;
-  options.maxVideoLengthMs = 0;
-  aRv = options.Init(aCx, aOptions.address());
+  mOptions.rotation = 0;
+  mOptions.maxFileSizeBytes = 0;
+  mOptions.maxVideoLengthMs = 0;
+  aRv = mOptions.Init(aCx, aOptions.address());
   if (aRv.Failed()) {
     return;
   }
 
   aRv = NotifyRecordingStatusChange(NS_LITERAL_STRING("starting"));
 
   #ifdef MOZ_B2G
   if (!mAudioChannelAgent) {
@@ -370,23 +370,63 @@ nsDOMCameraControl::StartRecording(JSCon
       mAudioChannelAgent->Init(AUDIO_CHANNEL_CONTENT, nullptr);
       // Video recording doesn't output any sound, so it's not necessary to check canPlay.
       int32_t canPlay;
       mAudioChannelAgent->StartPlaying(&canPlay);
     }
   }
   #endif
 
-  nsCOMPtr<nsIFile> folder;
-  aRv = storageArea.GetRootDirectoryForFile(filename, getter_AddRefs(folder));
+  nsCOMPtr<nsIDOMDOMRequest> request;
+  mDSFileDescriptor = new DeviceStorageFileDescriptor();
+  aRv = storageArea.CreateFileDescriptor(filename, mDSFileDescriptor.get(),
+                                         getter_AddRefs(request));
   if (aRv.Failed()) {
     return;
   }
-  aRv = mCameraControl->StartRecording(&options, folder, filename, onSuccess,
-                                       onError.WasPassed() ? onError.Value() : nullptr);
+
+  mOnSuccessCb = onSuccess;
+  mOnErrorCb = onError.WasPassed() ? onError.Value() : nullptr;
+
+  request->AddEventListener(NS_LITERAL_STRING("success"), this, false);
+  request->AddEventListener(NS_LITERAL_STRING("error"), this, false);
+}
+
+NS_IMETHODIMP
+nsDOMCameraControl::HandleEvent(nsIDOMEvent* aEvent)
+{
+  nsString  eventType;
+  aEvent->GetType(eventType);
+  ErrorResult rv;
+
+  if ((eventType.EqualsLiteral("success")) &&
+      mDSFileDescriptor->mFileDescriptor.IsValid()) {
+
+    rv = mCameraControl->StartRecording(&mOptions,
+                                        mDSFileDescriptor.get(),
+                                        mOnSuccessCb.get(),
+                                        mOnErrorCb.get());
+    if (!rv.Failed()) {
+      return rv.ErrorCode();
+    }
+
+    // An error happened. Fall through and call the error callback.
+  }
+
+  // We're already be on the main thread, so go ahead and call the
+  // error callback directly.
+
+  MOZ_ASSERT(NS_IsMainThread());
+
+  if (mOnErrorCb &&
+      nsDOMCameraManager::IsWindowStillActive(mWindow->WindowID())) {
+    mOnErrorCb->HandleEvent(NS_LITERAL_STRING("FAILURE"));
+  }
+
+  return NS_OK;
 }
 
 void
 nsDOMCameraControl::StopRecording(ErrorResult& aRv)
 {
   aRv = NotifyRecordingStatusChange(NS_LITERAL_STRING("shutdown"));
 
   #ifdef MOZ_B2G

--- a/dom/camera/DOMCameraControl.h
+++ b/dom/camera/DOMCameraControl.h
@@ -3,41 +3,44 @@
  * You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #ifndef DOM_CAMERA_DOMCAMERACONTROL_H
 #define DOM_CAMERA_DOMCAMERACONTROL_H
 
 #include "nsCOMPtr.h"
 #include "nsAutoPtr.h"
 #include "nsCycleCollectionParticipant.h"
+#include "nsIDOMEventListener.h"
 #include "DictionaryHelpers.h"
 #include "ICameraControl.h"
 #include "DOMCameraPreview.h"
 #include "nsIDOMCameraManager.h"
 #include "CameraCommon.h"
 #include "AudioChannelAgent.h"
 #include "nsProxyRelease.h"
 #include "nsHashPropertyBag.h"
+#include "DeviceStorage.h"
 
 class nsDOMDeviceStorage;
 class nsPIDOMWindow;
 
 namespace mozilla {
 namespace dom {
 class CameraPictureOptions;
 template<typename T> class Optional;
 }
 class ErrorResult;
 
 // Main camera control.
-class nsDOMCameraControl MOZ_FINAL : public nsISupports,
+class nsDOMCameraControl MOZ_FINAL : public nsIDOMEventListener,
                                      public nsWrapperCache
 {
 public:
   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+  NS_DECL_NSIDOMEVENTLISTENER
   NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(nsDOMCameraControl)
 
   nsDOMCameraControl(uint32_t aCameraId, nsIThread* aCameraThread,
                      nsICameraGetCameraCallback* onSuccess,
                      nsICameraErrorCallback* onError, nsPIDOMWindow* aWindow);
   nsresult Result(nsresult aResult,
                   const nsMainThreadPtrHandle<nsICameraGetCameraCallback>& onSuccess,
                   const nsMainThreadPtrHandle<nsICameraErrorCallback>& onError,
@@ -102,16 +105,21 @@ protected:
 
 private:
   nsDOMCameraControl(const nsDOMCameraControl&) MOZ_DELETE;
   nsDOMCameraControl& operator=(const nsDOMCameraControl&) MOZ_DELETE;
 
   virtual JSObject* WrapObject(JSContext* aCx, JS::Handle<JSObject*> aScope) MOZ_OVERRIDE;
   nsresult NotifyRecordingStatusChange(const nsString& aMsg);
 
+  mozilla::idl::CameraStartRecordingOptions mOptions;
+  nsRefPtr<DeviceStorageFileDescriptor> mDSFileDescriptor;
+  nsCOMPtr<nsICameraStartRecordingCallback> mOnSuccessCb;
+  nsCOMPtr<nsICameraErrorCallback> mOnErrorCb;
+
 protected:
   /* additional members */
   nsRefPtr<ICameraControl>        mCameraControl; // non-DOM camera control
   nsCOMPtr<nsICameraCapabilities> mDOMCapabilities;
   // An agent used to join audio channel service.
   nsCOMPtr<nsIAudioChannelAgent>  mAudioChannelAgent;
   nsCOMPtr<nsPIDOMWindow> mWindow;
 };

--- a/dom/camera/GonkCameraControl.cpp
+++ b/dom/camera/GonkCameraControl.cpp
@@ -37,16 +37,17 @@
 #include "nsIVolumeService.h"
 #include "DOMCameraManager.h"
 #include "GonkCameraHwMgr.h"
 #include "DOMCameraCapabilities.h"
 #include "DOMCameraControl.h"
 #include "GonkRecorderProfiles.h"
 #include "GonkCameraControl.h"
 #include "CameraCommon.h"
+#include "DeviceStorageFileDescriptor.h"
 
 using namespace mozilla;
 using namespace mozilla::dom;
 using namespace mozilla::layers;
 using namespace android;
 using mozilla::gfx::IntSize;
 
 /**
@@ -1018,17 +1019,17 @@ nsGonkCameraControl::TakePictureImpl(Tak
     SetParameter(CameraParameters::KEY_GPS_TIMESTAMP, nsPrintfCString("%lf", aTakePicture->mPosition.timestamp).get());
   }
 
   // Add the non-GPS timestamp.  The EXIF date/time field is formatted as
   // "YYYY:MM:DD HH:MM:SS", without room for a time-zone; as such, the time
   // is meant to be stored as a local time.  Since we are given seconds from
   // Epoch GMT, we use localtime_r() to handle the conversion.
   time_t time = aTakePicture->mDateTime;
-  if (time != aTakePicture->mDateTime) {
+  if ((uint64_t)time != aTakePicture->mDateTime) {
     DOM_CAMERA_LOGE("picture date/time '%llu' is too far in the future\n", aTakePicture->mDateTime);
   } else {
     struct tm t;
     if (localtime_r(&time, &t)) {
       char dateTime[20];
       if (strftime(dateTime, sizeof(dateTime), "%Y:%m:%d %T", &t)) {
         DOM_CAMERA_LOGI("setting picture date/time to %s\n", dateTime);
         // Not every platform defines a CameraParameters::KEY_EXIF_DATETIME;
@@ -1092,52 +1093,34 @@ nsGonkCameraControl::StartRecordingImpl(
   /**
    * Get the base path from device storage and append the app-specified
    * filename to it.  The filename may include a relative subpath
    * (e.g.) "DCIM/IMG_0001.jpg".
    *
    * The camera app needs to provide the file extension '.3gp' for now.
    * See bug 795202.
    */
-  nsCOMPtr<nsIFile> filename = aStartRecording->mFolder;
-  filename->AppendRelativePath(aStartRecording->mFilename);
-
-  nsString fullpath;
-  filename->GetPath(fullpath);
-
-  nsCOMPtr<nsIVolumeService> vs = do_GetService(NS_VOLUMESERVICE_CONTRACTID);
-  NS_ENSURE_TRUE(vs, NS_ERROR_FAILURE);
-
-  nsCOMPtr<nsIVolume> vol;
-  nsresult rv = vs->GetVolumeByPath(fullpath, getter_AddRefs(vol));
-  NS_ENSURE_SUCCESS(rv, NS_ERROR_INVALID_ARG);
-
-  nsString volName;
-  vol->GetName(volName);
-
-  mVideoFile = new DeviceStorageFile(NS_LITERAL_STRING("videos"),
-                                     volName,
-                                     aStartRecording->mFilename);
-
-  nsAutoCString nativeFilename;
-  filename->GetNativePath(nativeFilename);
-  DOM_CAMERA_LOGI("Video filename is '%s'\n", nativeFilename.get());
+  nsRefPtr<DeviceStorageFileDescriptor> dsfd = aStartRecording->mDSFileDescriptor;
+  NS_ENSURE_TRUE(dsfd, NS_ERROR_FAILURE);
+  nsAutoString fullPath;
+  mVideoFile = dsfd->mDSFile;
+  mVideoFile->GetFullPath(fullPath);
+  DOM_CAMERA_LOGI("Video filename is '%s'\n",
+                  NS_LossyConvertUTF16toASCII(fullPath).get());
 
   if (!mVideoFile->IsSafePath()) {
     DOM_CAMERA_LOGE("Invalid video file name\n");
     return NS_ERROR_INVALID_ARG;
   }
 
-  ScopedClose fd(open(nativeFilename.get(), O_RDWR | O_CREAT, 0644));
-  if (fd < 0) {
-    DOM_CAMERA_LOGE("Couldn't create file '%s': (%d) %s\n", nativeFilename.get(), errno, strerror(errno));
-    return NS_ERROR_FAILURE;
-  }
-
-  rv = SetupRecording(fd, aStartRecording->mOptions.rotation, aStartRecording->mOptions.maxFileSizeBytes, aStartRecording->mOptions.maxVideoLengthMs);
+  nsresult rv;
+  rv = SetupRecording(dsfd->mFileDescriptor.PlatformHandle(),
+                      aStartRecording->mOptions.rotation,
+                      aStartRecording->mOptions.maxFileSizeBytes,
+                      aStartRecording->mOptions.maxVideoLengthMs);
   NS_ENSURE_SUCCESS(rv, rv);
 
   if (mRecorder->start() != OK) {
     DOM_CAMERA_LOGE("mRecorder->start() failed\n");
     // important: we MUST destroy the recorder if start() fails!
     mRecorder = nullptr;
     return NS_ERROR_FAILURE;
   }

--- a/dom/camera/ICameraControl.h
+++ b/dom/camera/ICameraControl.h
@@ -5,32 +5,34 @@
 #ifndef DOM_CAMERA_ICAMERACONTROL_H
 #define DOM_CAMERA_ICAMERACONTROL_H
 
 #include "nsIFile.h"
 #include "nsIDOMCameraManager.h"
 #include "DictionaryHelpers.h"
 #include "CameraCommon.h"
 
+class DeviceStorageFileDescriptor;
+
 namespace mozilla {
 
 class DOMCameraPreview;
 class RecorderProfileManager;
 
 class ICameraControl
 {
 public:
   NS_INLINE_DECL_THREADSAFE_REFCOUNTING(ICameraControl)
 
   virtual nsresult GetPreviewStream(idl::CameraSize aSize, nsICameraPreviewStreamCallback* onSuccess, nsICameraErrorCallback* onError) = 0;
   virtual nsresult StartPreview(DOMCameraPreview* aDOMPreview) = 0;
   virtual void StopPreview() = 0;
   virtual nsresult AutoFocus(nsICameraAutoFocusCallback* onSuccess, nsICameraErrorCallback* onError) = 0;
   virtual nsresult TakePicture(const idl::CameraSize& aSize, int32_t aRotation, const nsAString& aFileFormat, idl::CameraPosition aPosition, uint64_t aDateTime, nsICameraTakePictureCallback* onSuccess, nsICameraErrorCallback* onError) = 0;
-  virtual nsresult StartRecording(idl::CameraStartRecordingOptions* aOptions, nsIFile* aFolder, const nsAString& aFilename, nsICameraStartRecordingCallback* onSuccess, nsICameraErrorCallback* onError) = 0;
+  virtual nsresult StartRecording(idl::CameraStartRecordingOptions* aOptions, DeviceStorageFileDescriptor *aFileDescriptor, nsICameraStartRecordingCallback* onSuccess, nsICameraErrorCallback* onError) = 0;
   virtual nsresult StopRecording() = 0;
   virtual nsresult GetPreviewStreamVideoMode(idl::CameraRecorderOptions* aOptions, nsICameraPreviewStreamCallback* onSuccess, nsICameraErrorCallback* onError) = 0;
   virtual nsresult ReleaseHardware(nsICameraReleaseCallback* onSuccess, nsICameraErrorCallback* onError) = 0;
 
   virtual nsresult Set(uint32_t aKey, const nsAString& aValue) = 0;
   virtual nsresult Get(uint32_t aKey, nsAString& aValue) = 0;
   virtual nsresult Set(uint32_t aKey, double aValue) = 0;
   virtual nsresult Get(uint32_t aKey, double* aValue) = 0;

--- a/dom/devicestorage/DeviceStorage.h
+++ b/dom/devicestorage/DeviceStorage.h
@@ -9,33 +9,37 @@
 
 #include "nsIDOMDeviceStorage.h"
 #include "nsIFile.h"
 #include "nsIPrincipal.h"
 #include "nsIObserver.h"
 #include "nsDOMEventTargetHelper.h"
 #include "mozilla/RefPtr.h"
 #include "mozilla/StaticPtr.h"
-#include "DOMRequest.h"
+#include "mozilla/dom/DOMRequest.h"
 
 #define DEVICESTORAGE_PICTURES   "pictures"
 #define DEVICESTORAGE_VIDEOS     "videos"
 #define DEVICESTORAGE_MUSIC      "music"
 #define DEVICESTORAGE_APPS       "apps"
 #define DEVICESTORAGE_SDCARD     "sdcard"
 #define DEVICESTORAGE_CRASHES    "crashes"
 
+class DeviceStorageFile;
 class nsIInputStream;
 
 namespace mozilla {
 namespace dom {
 class DeviceStorageEnumerationParameters;
 class DOMCursor;
 class DOMRequest;
 } // namespace dom
+namespace ipc {
+class FileDescriptor;
+}
 } // namespace mozilla
 
 class DeviceStorageFile MOZ_FINAL
   : public nsISupports {
 public:
   nsCOMPtr<nsIFile> mFile;
   nsString mStorageType;
   nsString mStorageName;
@@ -97,16 +101,17 @@ public:
   void GetStatus(nsAString& aStatus);
   void DoFormat(nsAString& aStatus);
   static void GetRootDirectoryForType(const nsAString& aStorageType,
                                       const nsAString& aStorageName,
                                       nsIFile** aFile);
 
   nsresult CalculateSizeAndModifiedDate();
   nsresult CalculateMimeType();
+  nsresult CreateFileDescriptor(mozilla::ipc::FileDescriptor& aFileDescriptor);
 
 private:
   void Init();
   void NormalizeFilePath();
   void AppendRelativePath(const nsAString& aPath);
   void AccumDirectoryUsage(nsIFile* aFile,
                            uint64_t* aPicturesSoFar,
                            uint64_t* aVideosSoFar,

new file mode 100644
--- /dev/null
+++ b/dom/devicestorage/DeviceStorageFileDescriptor.h
@@ -0,0 +1,20 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=2 sw=2 et tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef DeviceStorageFileDescriptor_h
+#define DeviceStorageFileDescriptor_h
+
+#include "mozilla/ipc/FileDescriptor.h"
+
+class DeviceStorageFileDescriptor MOZ_FINAL
+  : public mozilla::RefCounted<DeviceStorageFileDescriptor>
+{
+public:
+  nsRefPtr<DeviceStorageFile> mDSFile;
+  mozilla::ipc::FileDescriptor mFileDescriptor;
+};
+
+#endif

--- a/dom/devicestorage/DeviceStorageRequestChild.cpp
+++ b/dom/devicestorage/DeviceStorageRequestChild.cpp
@@ -1,35 +1,52 @@
 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
  * You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 
 #include "DeviceStorageRequestChild.h"
+#include "DeviceStorageFileDescriptor.h"
 #include "nsDeviceStorage.h"
 #include "nsDOMFile.h"
 #include "mozilla/dom/ipc/Blob.h"
 
 namespace mozilla {
 namespace dom {
 namespace devicestorage {
 
 DeviceStorageRequestChild::DeviceStorageRequestChild()
   : mCallback(nullptr)
 {
   MOZ_COUNT_CTOR(DeviceStorageRequestChild);
 }
 
 DeviceStorageRequestChild::DeviceStorageRequestChild(DOMRequest* aRequest,
-                                                     DeviceStorageFile* aFile)
+                                                     DeviceStorageFile* aDSFile)
   : mRequest(aRequest)
-  , mFile(aFile)
+  , mDSFile(aDSFile)
   , mCallback(nullptr)
 {
+  MOZ_ASSERT(aRequest);
+  MOZ_ASSERT(aDSFile);
+  MOZ_COUNT_CTOR(DeviceStorageRequestChild);
+}
+
+DeviceStorageRequestChild::DeviceStorageRequestChild(DOMRequest* aRequest,
+                                                     DeviceStorageFile* aDSFile,
+                                                     DeviceStorageFileDescriptor* aDSFileDescriptor)
+  : mRequest(aRequest)
+  , mDSFile(aDSFile)
+  , mDSFileDescriptor(aDSFileDescriptor)
+  , mCallback(nullptr)
+{
+  MOZ_ASSERT(aRequest);
+  MOZ_ASSERT(aDSFile);
+  MOZ_ASSERT(aDSFileDescriptor);
   MOZ_COUNT_CTOR(DeviceStorageRequestChild);
 }
 
 DeviceStorageRequestChild::~DeviceStorageRequestChild() {
   MOZ_COUNT_DTOR(DeviceStorageRequestChild);
 }
 
 bool
@@ -48,24 +65,40 @@ DeviceStorageRequestChild::
       ErrorResponse r = aValue;
       mRequest->FireError(r.error());
       break;
     }
 
     case DeviceStorageResponseValue::TSuccessResponse:
     {
       nsString fullPath;
-      mFile->GetFullPath(fullPath);
+      mDSFile->GetFullPath(fullPath);
       AutoJSContext cx;
       JS::Rooted<JS::Value> result(cx,
         StringToJsval(mRequest->GetOwner(), fullPath));
       mRequest->FireSuccess(result);
       break;
     }
 
+    case DeviceStorageResponseValue::TFileDescriptorResponse:
+    {
+      FileDescriptorResponse r = aValue;
+
+      nsString fullPath;
+      mDSFile->GetFullPath(fullPath);
+      AutoJSContext cx;
+      JS::Rooted<JS::Value> result(cx,
+        StringToJsval(mRequest->GetOwner(), fullPath));
+
+      mDSFileDescriptor->mDSFile = mDSFile;
+      mDSFileDescriptor->mFileDescriptor = r.fileDescriptor();
+      mRequest->FireSuccess(result);
+      break;
+    }
+
     case DeviceStorageResponseValue::TBlobResponse:
     {
       BlobResponse r = aValue;
       BlobChild* actor = static_cast<BlobChild*>(r.blobChild());
       nsCOMPtr<nsIDOMBlob> blob = actor->GetBlob();
 
       nsCOMPtr<nsIDOMFile> file = do_QueryInterface(blob);
       AutoJSContext cx;

--- a/dom/devicestorage/DeviceStorageRequestChild.h
+++ b/dom/devicestorage/DeviceStorageRequestChild.h
@@ -2,44 +2,50 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
  * You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #ifndef mozilla_dom_devicestorage_DeviceStorageRequestChild_h
 #define mozilla_dom_devicestorage_DeviceStorageRequestChild_h
 
 #include "mozilla/dom/devicestorage/PDeviceStorageRequestChild.h"
-#include "DOMRequest.h"
 
 class DeviceStorageFile;
+class DeviceStorageFileDescriptor;
 
 namespace mozilla {
 namespace dom {
+
+class DOMRequest;
+
 namespace devicestorage {
 
 class DeviceStorageRequestChildCallback
 {
   public:
     virtual void RequestComplete() = 0;
 };
 
 class DeviceStorageRequestChild : public PDeviceStorageRequestChild
 {
 public:
   DeviceStorageRequestChild();
   DeviceStorageRequestChild(DOMRequest* aRequest, DeviceStorageFile* aFile);
+  DeviceStorageRequestChild(DOMRequest* aRequest, DeviceStorageFile* aFile,
+                            DeviceStorageFileDescriptor* aFileDescrptor);
   ~DeviceStorageRequestChild();
 
   void SetCallback(class DeviceStorageRequestChildCallback *aCallback);
 
   virtual bool Recv__delete__(const DeviceStorageResponseValue& value);
 
 private:
   nsRefPtr<DOMRequest> mRequest;
-  nsRefPtr<DeviceStorageFile> mFile;
+  nsRefPtr<DeviceStorageFile> mDSFile;
+  nsRefPtr<DeviceStorageFileDescriptor> mDSFileDescriptor;
 
   DeviceStorageRequestChildCallback* mCallback;
 };
 
 } // namespace devicestorage
 } // namespace dom
 } // namespace mozilla
 

--- a/dom/devicestorage/DeviceStorageRequestParent.cpp
+++ b/dom/devicestorage/DeviceStorageRequestParent.cpp
@@ -24,17 +24,17 @@ DeviceStorageRequestParent::DeviceStorag
   : mParams(aParams)
   , mMutex("DeviceStorageRequestParent::mMutex")
   , mActorDestoryed(false)
 {
   MOZ_COUNT_CTOR(DeviceStorageRequestParent);
 
   DebugOnly<DeviceStorageUsedSpaceCache*> usedSpaceCache
     = DeviceStorageUsedSpaceCache::CreateOrGet();
-  NS_ASSERTION(usedSpaceCache, "DeviceStorageUsedSpaceCache is null");
+  MOZ_ASSERT(usedSpaceCache);
 }
 
 void
 DeviceStorageRequestParent::Dispatch()
 {
   switch (mParams.type()) {
     case DeviceStorageParams::TDeviceStorageAddParams:
     {
@@ -48,71 +48,87 @@ DeviceStorageRequestParent::Dispatch()
 
       nsCOMPtr<nsIInputStream> stream;
       blob->GetInternalStream(getter_AddRefs(stream));
 
       nsRefPtr<CancelableRunnable> r = new WriteFileEvent(this, dsf, stream);
 
       nsCOMPtr<nsIEventTarget> target
         = do_GetService(NS_STREAMTRANSPORTSERVICE_CONTRACTID);
-      NS_ASSERTION(target, "Must have stream transport service");
+      MOZ_ASSERT(target);
+      target->Dispatch(r, NS_DISPATCH_NORMAL);
+      break;
+    }
+
+    case DeviceStorageParams::TDeviceStorageCreateFdParams:
+    {
+      DeviceStorageCreateFdParams p = mParams;
+
+      nsRefPtr<DeviceStorageFile> dsf =
+        new DeviceStorageFile(p.type(), p.storageName(), p.relpath());
+
+      nsRefPtr<CancelableRunnable> r = new CreateFdEvent(this, dsf);
+
+      nsCOMPtr<nsIEventTarget> target
+        = do_GetService(NS_STREAMTRANSPORTSERVICE_CONTRACTID);
+      MOZ_ASSERT(target);
       target->Dispatch(r, NS_DISPATCH_NORMAL);
       break;
     }
 
     case DeviceStorageParams::TDeviceStorageGetParams:
     {
       DeviceStorageGetParams p = mParams;
       nsRefPtr<DeviceStorageFile> dsf =
         new DeviceStorageFile(p.type(), p.storageName(),
                               p.rootDir(), p.relpath());
       nsRefPtr<CancelableRunnable> r = new ReadFileEvent(this, dsf);
 
       nsCOMPtr<nsIEventTarget> target
         = do_GetService(NS_STREAMTRANSPORTSERVICE_CONTRACTID);
-      NS_ASSERTION(target, "Must have stream transport service");
+      MOZ_ASSERT(target);
       target->Dispatch(r, NS_DISPATCH_NORMAL);
       break;
     }
 
     case DeviceStorageParams::TDeviceStorageDeleteParams:
     {
       DeviceStorageDeleteParams p = mParams;
 
       nsRefPtr<DeviceStorageFile> dsf =
         new DeviceStorageFile(p.type(), p.storageName(), p.relpath());
       nsRefPtr<CancelableRunnable> r = new DeleteFileEvent(this, dsf);
 
       nsCOMPtr<nsIEventTarget> target
         = do_GetService(NS_STREAMTRANSPORTSERVICE_CONTRACTID);
-      NS_ASSERTION(target, "Must have stream transport service");
+      MOZ_ASSERT(target);
       target->Dispatch(r, NS_DISPATCH_NORMAL);
       break;
     }
 
     case DeviceStorageParams::TDeviceStorageFreeSpaceParams:
     {
       DeviceStorageFreeSpaceParams p = mParams;
 
       nsRefPtr<DeviceStorageFile> dsf =
         new DeviceStorageFile(p.type(), p.storageName());
       nsRefPtr<FreeSpaceFileEvent> r = new FreeSpaceFileEvent(this, dsf);
 
       nsCOMPtr<nsIEventTarget> target
         = do_GetService(NS_STREAMTRANSPORTSERVICE_CONTRACTID);
-      NS_ASSERTION(target, "Must have stream transport service");
+      MOZ_ASSERT(target);
       target->Dispatch(r, NS_DISPATCH_NORMAL);
       break;
     }
 
     case DeviceStorageParams::TDeviceStorageUsedSpaceParams:
     {
       DeviceStorageUsedSpaceCache* usedSpaceCache
         = DeviceStorageUsedSpaceCache::CreateOrGet();
-      NS_ASSERTION(usedSpaceCache, "DeviceStorageUsedSpaceCache is null");
+      MOZ_ASSERT(usedSpaceCache);
 
       DeviceStorageUsedSpaceParams p = mParams;
 
       nsRefPtr<DeviceStorageFile> dsf =
         new DeviceStorageFile(p.type(), p.storageName());
       nsRefPtr<UsedSpaceFileEvent> r = new UsedSpaceFileEvent(this, dsf);
 
       usedSpaceCache->Dispatch(r);
@@ -122,44 +138,46 @@ DeviceStorageRequestParent::Dispatch()
     case DeviceStorageParams::TDeviceStorageAvailableParams:
     {
       DeviceStorageAvailableParams p = mParams;
 
       nsRefPtr<DeviceStorageFile> dsf =
         new DeviceStorageFile(p.type(), p.storageName());
       nsRefPtr<PostAvailableResultEvent> r
         = new PostAvailableResultEvent(this, dsf);
-      NS_DispatchToMainThread(r);
+      DebugOnly<nsresult> rv = NS_DispatchToMainThread(r);
+      MOZ_ASSERT(NS_SUCCEEDED(rv));
       break;
     }
 
     case DeviceStorageParams::TDeviceStorageFormatParams:
     {
       DeviceStorageFormatParams p = mParams;
 
       nsRefPtr<DeviceStorageFile> dsf =
         new DeviceStorageFile(p.type(), p.storageName());
       nsRefPtr<PostFormatResultEvent> r
         = new PostFormatResultEvent(this, dsf);
-      NS_DispatchToMainThread(r);
+      DebugOnly<nsresult> rv = NS_DispatchToMainThread(r);
+      MOZ_ASSERT(NS_SUCCEEDED(rv));
       break;
     }
 
     case DeviceStorageParams::TDeviceStorageEnumerationParams:
     {
       DeviceStorageEnumerationParams p = mParams;
       nsRefPtr<DeviceStorageFile> dsf
         = new DeviceStorageFile(p.type(), p.storageName(),
                                 p.rootdir(), NS_LITERAL_STRING(""));
       nsRefPtr<CancelableRunnable> r
         = new EnumerateFileEvent(this, dsf, p.since());
 
       nsCOMPtr<nsIEventTarget> target
         = do_GetService(NS_STREAMTRANSPORTSERVICE_CONTRACTID);
-      NS_ASSERTION(target, "Must have stream transport service");
+      MOZ_ASSERT(target);
       target->Dispatch(r, NS_DISPATCH_NORMAL);
       break;
     }
     default:
     {
       NS_RUNTIMEABORT("not reached");
       break;
     }
@@ -182,16 +200,24 @@ DeviceStorageRequestParent::EnsureRequir
     case DeviceStorageParams::TDeviceStorageAddParams:
     {
       DeviceStorageAddParams p = mParams;
       type = p.type();
       requestType = DEVICE_STORAGE_REQUEST_CREATE;
       break;
     }
 
+    case DeviceStorageParams::TDeviceStorageCreateFdParams:
+    {
+      DeviceStorageCreateFdParams p = mParams;
+      type = p.type();
+      requestType = DEVICE_STORAGE_REQUEST_CREATEFD;
+      break;
+    }
+
     case DeviceStorageParams::TDeviceStorageGetParams:
     {
       DeviceStorageGetParams p = mParams;
       type = p.type();
       requestType = DEVICE_STORAGE_REQUEST_READ;
       break;
     }
 
@@ -307,17 +333,17 @@ DeviceStorageRequestParent::PostFreeSpac
 {
 }
 
 DeviceStorageRequestParent::PostFreeSpaceResultEvent::
   ~PostFreeSpaceResultEvent() {}
 
 nsresult
 DeviceStorageRequestParent::PostFreeSpaceResultEvent::CancelableRun() {
-  NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
+  MOZ_ASSERT(NS_IsMainThread());
 
   FreeSpaceStorageResponse response(mFreeSpace);
   unused << mParent->Send__delete__(mParent, response);
   return NS_OK;
 }
 
 DeviceStorageRequestParent::PostUsedSpaceResultEvent::
   PostUsedSpaceResultEvent(DeviceStorageRequestParent* aParent,
@@ -329,17 +355,17 @@ DeviceStorageRequestParent::PostUsedSpac
 {
 }
 
 DeviceStorageRequestParent::PostUsedSpaceResultEvent::
   ~PostUsedSpaceResultEvent() {}
 
 nsresult
 DeviceStorageRequestParent::PostUsedSpaceResultEvent::CancelableRun() {
-  NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
+  MOZ_ASSERT(NS_IsMainThread());
 
   UsedSpaceStorageResponse response(mUsedSpace);
   unused << mParent->Send__delete__(mParent, response);
   return NS_OK;
 }
 
 DeviceStorageRequestParent::PostErrorEvent::
   PostErrorEvent(DeviceStorageRequestParent* aParent, const char* aError)
@@ -347,34 +373,34 @@ DeviceStorageRequestParent::PostErrorEve
 {
   CopyASCIItoUTF16(aError, mError);
 }
 
 DeviceStorageRequestParent::PostErrorEvent::~PostErrorEvent() {}
 
 nsresult
 DeviceStorageRequestParent::PostErrorEvent::CancelableRun() {
-  NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
+  MOZ_ASSERT(NS_IsMainThread());
 
   ErrorResponse response(mError);
   unused << mParent->Send__delete__(mParent, response);
   return NS_OK;
 }
 
 DeviceStorageRequestParent::PostSuccessEvent::
   PostSuccessEvent(DeviceStorageRequestParent* aParent)
   : CancelableRunnable(aParent)
 {
 }
 
 DeviceStorageRequestParent::PostSuccessEvent::~PostSuccessEvent() {}
 
 nsresult
 DeviceStorageRequestParent::PostSuccessEvent::CancelableRun() {
-  NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
+  MOZ_ASSERT(NS_IsMainThread());
 
   SuccessResponse response;
   unused << mParent->Send__delete__(mParent, response);
   return NS_OK;
 }
 
 DeviceStorageRequestParent::PostBlobSuccessEvent::
   PostBlobSuccessEvent(DeviceStorageRequestParent* aParent,
@@ -389,17 +415,17 @@ DeviceStorageRequestParent::PostBlobSucc
   , mMimeType(aMimeType)
 {
 }
 
 DeviceStorageRequestParent::PostBlobSuccessEvent::~PostBlobSuccessEvent() {}
 
 nsresult
 DeviceStorageRequestParent::PostBlobSuccessEvent::CancelableRun() {
-  NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
+  MOZ_ASSERT(NS_IsMainThread());
 
   nsString mime;
   CopyASCIItoUTF16(mMimeType, mime);
 
   nsString fullPath;
   mFile->GetFullPath(fullPath);
   nsCOMPtr<nsIDOMBlob> blob = new nsDOMFileFile(fullPath, mime, mLength, 
                                                 mFile->mFile,
@@ -432,23 +458,64 @@ DeviceStorageRequestParent::PostEnumerat
 {
 }
 
 DeviceStorageRequestParent::PostEnumerationSuccessEvent::
   ~PostEnumerationSuccessEvent() {}
 
 nsresult
 DeviceStorageRequestParent::PostEnumerationSuccessEvent::CancelableRun() {
-  NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
+  MOZ_ASSERT(NS_IsMainThread());
 
   EnumerationResponse response(mStorageType, mRelPath, mPaths);
   unused << mParent->Send__delete__(mParent, response);
   return NS_OK;
 }
 
+DeviceStorageRequestParent::CreateFdEvent::
+  CreateFdEvent(DeviceStorageRequestParent* aParent,
+                 DeviceStorageFile* aFile)
+  : CancelableRunnable(aParent)
+  , mFile(aFile)
+{
+}
+
+DeviceStorageRequestParent::CreateFdEvent::~CreateFdEvent()
+{
+}
+
+nsresult
+DeviceStorageRequestParent::CreateFdEvent::CancelableRun()
+{
+  MOZ_ASSERT(!NS_IsMainThread());
+
+  nsRefPtr<nsRunnable> r;
+
+  bool check = false;
+  mFile->mFile->Exists(&check);
+  if (check) {
+    nsCOMPtr<PostErrorEvent> event
+      = new PostErrorEvent(mParent, POST_ERROR_EVENT_FILE_EXISTS);
+    return NS_DispatchToMainThread(event);
+  }
+
+  FileDescriptor fileDescriptor;
+  nsresult rv = mFile->CreateFileDescriptor(fileDescriptor);
+  if (NS_FAILED(rv)) {
+    NS_WARNING("CreateFileDescriptor failed");
+    mFile->Dump("CreateFileDescriptor failed");
+    r = new PostErrorEvent(mParent, POST_ERROR_EVENT_UNKNOWN);
+  }
+  else {
+    r = new PostFileDescriptorResultEvent(mParent, fileDescriptor);
+  }
+
+  return NS_DispatchToMainThread(r);
+}
+
 DeviceStorageRequestParent::WriteFileEvent::
   WriteFileEvent(DeviceStorageRequestParent* aParent,
                  DeviceStorageFile* aFile,
                  nsIInputStream* aInputStream)
   : CancelableRunnable(aParent)
   , mFile(aFile)
   , mInputStream(aInputStream)
 {
@@ -456,80 +523,75 @@ DeviceStorageRequestParent::WriteFileEve
 
 DeviceStorageRequestParent::WriteFileEvent::~WriteFileEvent()
 {
 }
 
 nsresult
 DeviceStorageRequestParent::WriteFileEvent::CancelableRun()
 {
-  NS_ASSERTION(!NS_IsMainThread(), "Wrong thread!");
+  MOZ_ASSERT(!NS_IsMainThread());
 
   nsRefPtr<nsRunnable> r;
 
   if (!mInputStream) {
     r = new PostErrorEvent(mParent, POST_ERROR_EVENT_UNKNOWN);
-    NS_DispatchToMainThread(r);
-    return NS_OK;
+    return NS_DispatchToMainThread(r);
   }
 
   bool check = false;
   mFile->mFile->Exists(&check);
   if (check) {
     nsCOMPtr<PostErrorEvent> event
       = new PostErrorEvent(mParent, POST_ERROR_EVENT_FILE_EXISTS);
-    NS_DispatchToMainThread(event);
-    return NS_OK;
+    return NS_DispatchToMainThread(event);
   }
 
   nsresult rv = mFile->Write(mInputStream);
 
   if (NS_FAILED(rv)) {
     r = new PostErrorEvent(mParent, POST_ERROR_EVENT_UNKNOWN);
   }
   else {
     r = new PostPathResultEvent(mParent, mFile->mPath);
   }
 
-  NS_DispatchToMainThread(r);
-  return NS_OK;
+  return NS_DispatchToMainThread(r);
 }
 
-
 DeviceStorageRequestParent::DeleteFileEvent::
   DeleteFileEvent(DeviceStorageRequestParent* aParent, DeviceStorageFile* aFile)
   : CancelableRunnable(aParent)
   , mFile(aFile)
 {
 }
 
 DeviceStorageRequestParent::DeleteFileEvent::~DeleteFileEvent()
 {
 }
 
 nsresult
 DeviceStorageRequestParent::DeleteFileEvent::CancelableRun()
 {
-  NS_ASSERTION(!NS_IsMainThread(), "Wrong thread!");
+  MOZ_ASSERT(!NS_IsMainThread());
 
   mFile->Remove();
 
   nsRefPtr<nsRunnable> r;
 
   bool check = false;
   mFile->mFile->Exists(&check);
   if (check) {
     r = new PostErrorEvent(mParent, POST_ERROR_EVENT_UNKNOWN);
   }
   else {
     r = new PostPathResultEvent(mParent, mFile->mPath);
   }
 
-  NS_DispatchToMainThread(r);
-  return NS_OK;
+  return NS_DispatchToMainThread(r);
 }
 
 DeviceStorageRequestParent::FreeSpaceFileEvent::
   FreeSpaceFileEvent(DeviceStorageRequestParent* aParent,
                      DeviceStorageFile* aFile)
   : CancelableRunnable(aParent)
   , mFile(aFile)
 {
@@ -537,27 +599,26 @@ DeviceStorageRequestParent::FreeSpaceFil
 
 DeviceStorageRequestParent::FreeSpaceFileEvent::~FreeSpaceFileEvent()
 {
 }
 
 nsresult
 DeviceStorageRequestParent::FreeSpaceFileEvent::CancelableRun()
 {
-  NS_ASSERTION(!NS_IsMainThread(), "Wrong thread!");
+  MOZ_ASSERT(!NS_IsMainThread());
 
   int64_t freeSpace = 0;
   if (mFile) {
     mFile->GetDiskFreeSpace(&freeSpace);
   }
 
   nsCOMPtr<nsIRunnable> r;
   r = new PostFreeSpaceResultEvent(mParent, static_cast<uint64_t>(freeSpace));
-  NS_DispatchToMainThread(r);
-  return NS_OK;
+  return NS_DispatchToMainThread(r);
 }
 
 DeviceStorageRequestParent::UsedSpaceFileEvent::
   UsedSpaceFileEvent(DeviceStorageRequestParent* aParent,
                      DeviceStorageFile* aFile)
   : CancelableRunnable(aParent)
   , mFile(aFile)
 {
@@ -565,17 +626,17 @@ DeviceStorageRequestParent::UsedSpaceFil
 
 DeviceStorageRequestParent::UsedSpaceFileEvent::~UsedSpaceFileEvent()
 {
 }
 
 nsresult
 DeviceStorageRequestParent::UsedSpaceFileEvent::CancelableRun()
 {
-  NS_ASSERTION(!NS_IsMainThread(), "Wrong thread!");
+  MOZ_ASSERT(!NS_IsMainThread());
 
   uint64_t picturesUsage = 0, videosUsage = 0, musicUsage = 0, totalUsage = 0;
   mFile->AccumDiskUsage(&picturesUsage, &videosUsage,
                         &musicUsage, &totalUsage);
   nsCOMPtr<nsIRunnable> r;
   if (mFile->mStorageType.EqualsLiteral(DEVICESTORAGE_PICTURES)) {
     r = new PostUsedSpaceResultEvent(mParent, mFile->mStorageType,
                                      picturesUsage);
@@ -583,18 +644,17 @@ DeviceStorageRequestParent::UsedSpaceFil
   else if (mFile->mStorageType.EqualsLiteral(DEVICESTORAGE_VIDEOS)) {
     r = new PostUsedSpaceResultEvent(mParent, mFile->mStorageType, videosUsage);
   }
   else if (mFile->mStorageType.EqualsLiteral(DEVICESTORAGE_MUSIC)) {
     r = new PostUsedSpaceResultEvent(mParent, mFile->mStorageType, musicUsage);
   } else {
     r = new PostUsedSpaceResultEvent(mParent, mFile->mStorageType, totalUsage);
   }
-  NS_DispatchToMainThread(r);
-  return NS_OK;
+  return NS_DispatchToMainThread(r);
 }
 
 DeviceStorageRequestParent::ReadFileEvent::
   ReadFileEvent(DeviceStorageRequestParent* aParent, DeviceStorageFile* aFile)
   : CancelableRunnable(aParent)
   , mFile(aFile)
 {
   nsCOMPtr<nsIMIMEService> mimeService
@@ -609,48 +669,44 @@ DeviceStorageRequestParent::ReadFileEven
 
 DeviceStorageRequestParent::ReadFileEvent::~ReadFileEvent()
 {
 }
 
 nsresult
 DeviceStorageRequestParent::ReadFileEvent::CancelableRun()
 {
-  NS_ASSERTION(!NS_IsMainThread(), "Wrong thread!");
+  MOZ_ASSERT(!NS_IsMainThread());
 
   nsCOMPtr<nsIRunnable> r;
   bool check = false;
   mFile->mFile->Exists(&check);
 
   if (!check) {
     r = new PostErrorEvent(mParent, POST_ERROR_EVENT_FILE_DOES_NOT_EXIST);
-    NS_DispatchToMainThread(r);
-    return NS_OK;
+    return NS_DispatchToMainThread(r);
   }
 
   int64_t fileSize;
   nsresult rv = mFile->mFile->GetFileSize(&fileSize);
   if (NS_FAILED(rv)) {
     r = new PostErrorEvent(mParent, POST_ERROR_EVENT_UNKNOWN);
-    NS_DispatchToMainThread(r);
-    return NS_OK;
+    return NS_DispatchToMainThread(r);
   }
 
   PRTime modDate;
   rv = mFile->mFile->GetLastModifiedTime(&modDate);
   if (NS_FAILED(rv)) {
     r = new PostErrorEvent(mParent, POST_ERROR_EVENT_UNKNOWN);
-    NS_DispatchToMainThread(r);
-    return NS_OK;
+    return NS_DispatchToMainThread(r);
   }
 
   r = new PostBlobSuccessEvent(mParent, mFile, static_cast<uint64_t>(fileSize),
                                mMimeType, modDate);
-  NS_DispatchToMainThread(r);
-  return NS_OK;
+  return NS_DispatchToMainThread(r);
 }
 
 DeviceStorageRequestParent::EnumerateFileEvent::
   EnumerateFileEvent(DeviceStorageRequestParent* aParent,
                      DeviceStorageFile* aFile,
                      uint64_t aSince)
   : CancelableRunnable(aParent)
   , mFile(aFile)
@@ -660,44 +716,42 @@ DeviceStorageRequestParent::EnumerateFil
 
 DeviceStorageRequestParent::EnumerateFileEvent::~EnumerateFileEvent()
 {
 }
 
 nsresult
 DeviceStorageRequestParent::EnumerateFileEvent::CancelableRun()
 {
-  NS_ASSERTION(!NS_IsMainThread(), "Wrong thread!");
+  MOZ_ASSERT(!NS_IsMainThread());
 
   nsCOMPtr<nsIRunnable> r;
   if (mFile->mFile) {
     bool check = false;
     mFile->mFile->Exists(&check);
     if (!check) {
       r = new PostErrorEvent(mParent, POST_ERROR_EVENT_FILE_DOES_NOT_EXIST);
-      NS_DispatchToMainThread(r);
-      return NS_OK;
+      return NS_DispatchToMainThread(r);
     }
   }
 
   nsTArray<nsRefPtr<DeviceStorageFile> > files;
   mFile->CollectFiles(files, mSince);
 
   InfallibleTArray<DeviceStorageFileValue> values;
 
   uint32_t count = files.Length();
   for (uint32_t i = 0; i < count; i++) {
     DeviceStorageFileValue dsvf(files[i]->mStorageName, files[i]->mPath);
     values.AppendElement(dsvf);
   }
 
   r = new PostEnumerationSuccessEvent(mParent, mFile->mStorageType,
                                       mFile->mRootDir, values);
-  NS_DispatchToMainThread(r);
-  return NS_OK;
+  return NS_DispatchToMainThread(r);
 }
 
 
 DeviceStorageRequestParent::PostPathResultEvent::
   PostPathResultEvent(DeviceStorageRequestParent* aParent,
                       const nsAString& aPath)
   : CancelableRunnable(aParent)
   , mPath(aPath)
@@ -706,40 +760,63 @@ DeviceStorageRequestParent::PostPathResu
 
 DeviceStorageRequestParent::PostPathResultEvent::~PostPathResultEvent()
 {
 }
 
 nsresult
 DeviceStorageRequestParent::PostPathResultEvent::CancelableRun()
 {
-  NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
+  MOZ_ASSERT(NS_IsMainThread());
 
   SuccessResponse response;
   unused << mParent->Send__delete__(mParent, response);
   return NS_OK;
 }
 
+DeviceStorageRequestParent::PostFileDescriptorResultEvent::
+  PostFileDescriptorResultEvent(DeviceStorageRequestParent* aParent,
+                                const FileDescriptor& aFileDescriptor)
+  : CancelableRunnable(aParent)
+  , mFileDescriptor(aFileDescriptor)
+{
+}
+
+DeviceStorageRequestParent::PostFileDescriptorResultEvent::
+  ~PostFileDescriptorResultEvent()
+{
+}
+
+nsresult
+DeviceStorageRequestParent::PostFileDescriptorResultEvent::CancelableRun()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  FileDescriptorResponse response(mFileDescriptor);
+  unused << mParent->Send__delete__(mParent, response);
+  return NS_OK;
+}
+
 DeviceStorageRequestParent::PostAvailableResultEvent::
   PostAvailableResultEvent(DeviceStorageRequestParent* aParent,
                            DeviceStorageFile* aFile)
   : CancelableRunnable(aParent)
   , mFile(aFile)
 {
 }
 
 DeviceStorageRequestParent::PostAvailableResultEvent::
   ~PostAvailableResultEvent()
 {
 }
 
 nsresult
 DeviceStorageRequestParent::PostAvailableResultEvent::CancelableRun()
 {
-  NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
+  MOZ_ASSERT(NS_IsMainThread());
 
   nsString state = NS_LITERAL_STRING("unavailable");
   if (mFile) {
     mFile->GetStatus(state);
   }
 
   AvailableStorageResponse response(state);
   unused << mParent->Send__delete__(mParent, response);
@@ -757,17 +834,17 @@ DeviceStorageRequestParent::PostFormatRe
 DeviceStorageRequestParent::PostFormatResultEvent::
   ~PostFormatResultEvent()
 {
 }
 
 nsresult
 DeviceStorageRequestParent::PostFormatResultEvent::CancelableRun()
 {
-  NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
+  MOZ_ASSERT(NS_IsMainThread());
 
   nsString state = NS_LITERAL_STRING("unavailable");
   if (mFile) {
     mFile->DoFormat(state);
   }
 
   FormatStorageResponse response(state);
   unused << mParent->Send__delete__(mParent, response);

--- a/dom/devicestorage/DeviceStorageRequestParent.h
+++ b/dom/devicestorage/DeviceStorageRequestParent.h
@@ -114,16 +114,26 @@ private:
       virtual ~PostEnumerationSuccessEvent();
       virtual nsresult CancelableRun();
     private:
       const nsString mStorageType;
       const nsString mRelPath;
       InfallibleTArray<DeviceStorageFileValue> mPaths;
   };
 
+  class CreateFdEvent : public CancelableRunnable
+  {
+    public:
+      CreateFdEvent(DeviceStorageRequestParent* aParent, DeviceStorageFile* aFile);
+      virtual ~CreateFdEvent();
+      virtual nsresult CancelableRun();
+    private:
+      nsRefPtr<DeviceStorageFile> mFile;
+  };
+
   class WriteFileEvent : public CancelableRunnable
   {
     public:
       WriteFileEvent(DeviceStorageRequestParent* aParent, DeviceStorageFile* aFile, nsIInputStream* aInputStream);
       virtual ~WriteFileEvent();
       virtual nsresult CancelableRun();
     private:
       nsRefPtr<DeviceStorageFile> mFile;
@@ -188,16 +198,28 @@ private:
       PostPathResultEvent(DeviceStorageRequestParent* aParent, const nsAString& aPath);
       virtual ~PostPathResultEvent();
       virtual nsresult CancelableRun();
     private:
       nsRefPtr<DeviceStorageFile> mFile;
       nsString mPath;
   };
 
+  class PostFileDescriptorResultEvent : public CancelableRunnable
+  {
+    public:
+      PostFileDescriptorResultEvent(DeviceStorageRequestParent* aParent,
+                                    const FileDescriptor& aFileDescriptor);
+      virtual ~PostFileDescriptorResultEvent();
+      virtual nsresult CancelableRun();
+    private:
+      nsRefPtr<DeviceStorageFile> mFile;
+      FileDescriptor mFileDescriptor;
+  };
+
  class PostFreeSpaceResultEvent : public CancelableRunnable
  {
     public:
       PostFreeSpaceResultEvent(DeviceStorageRequestParent* aParent,
                                uint64_t aFreeSpace);
       virtual ~PostFreeSpaceResultEvent();
       virtual nsresult CancelableRun();
     private:

--- a/dom/devicestorage/PDeviceStorageRequest.ipdl
+++ b/dom/devicestorage/PDeviceStorageRequest.ipdl
@@ -15,16 +15,21 @@ struct ErrorResponse
 {
   nsString error;
 };
 
 struct SuccessResponse
 {
 };
 
+struct FileDescriptorResponse
+{
+  FileDescriptor fileDescriptor;
+};
+
 struct BlobResponse
 {
   PBlob blob;
 };
 
 struct DeviceStorageFileValue
 {
   nsString storageName;
@@ -57,16 +62,17 @@ struct FormatStorageResponse
 {
   nsString mountState;
 };
 
 union DeviceStorageResponseValue
 {
   ErrorResponse;
   SuccessResponse;
+  FileDescriptorResponse;
   BlobResponse;
   EnumerationResponse;
   FreeSpaceStorageResponse;
   UsedSpaceStorageResponse;
   AvailableStorageResponse;
   FormatStorageResponse;
 };
 

--- a/dom/devicestorage/moz.build
+++ b/dom/devicestorage/moz.build
@@ -3,16 +3,17 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 TEST_DIRS += ['test', 'ipc']
 
 EXPORTS += [
     'DeviceStorage.h',
+    'DeviceStorageFileDescriptor.h',
     'nsDeviceStorage.h',
 ]
 
 EXPORTS.mozilla.dom.devicestorage += [
     'DeviceStorageRequestChild.h',
     'DeviceStorageRequestParent.h',
 ]
 

--- a/dom/devicestorage/nsDeviceStorage.cpp
+++ b/dom/devicestorage/nsDeviceStorage.cpp
@@ -33,27 +33,29 @@
 #include "nsCycleCollectionParticipant.h"
 #include "nsIPrincipal.h"
 #include "nsJSUtils.h"
 #include "DictionaryHelpers.h"
 #include "nsContentUtils.h"
 #include "nsCxPusher.h"
 #include "nsXULAppAPI.h"
 #include "TabChild.h"
+#include "DeviceStorageFileDescriptor.h"
 #include "DeviceStorageRequestChild.h"
 #include "nsIDOMDeviceStorageChangeEvent.h"
 #include "nsCRT.h"
 #include "nsIObserverService.h"
 #include "GeneratedEvents.h"
 #include "nsIMIMEService.h"
 #include "nsCExternalHandlerService.h"
 #include "nsIPermissionManager.h"
 #include "nsIStringBundle.h"
 #include "nsIDocument.h"
 #include <algorithm>
+#include "private/pprio.h"
 
 #include "mozilla/dom/DeviceStorageBinding.h"
 
 // Microsoft's API Name hackery sucks
 #undef CreateEvent
 
 #ifdef MOZ_WIDGET_GONK
 #include "nsIVolume.h"
@@ -62,16 +64,17 @@
 
 #define DEVICESTORAGE_PROPERTIES \
   "chrome://global/content/devicestorage.properties"
 #define DEFAULT_THREAD_TIMEOUT_MS 30000
 
 using namespace mozilla;
 using namespace mozilla::dom;
 using namespace mozilla::dom::devicestorage;
+using namespace mozilla::ipc;
 
 #include "nsDirectoryServiceDefs.h"
 
 StaticAutoPtr<DeviceStorageUsedSpaceCache>
   DeviceStorageUsedSpaceCache::sDeviceStorageUsedSpaceCache;
 
 DeviceStorageUsedSpaceCache::DeviceStorageUsedSpaceCache()
 {
@@ -244,17 +247,17 @@ DeviceStorageTypeChecker::InitFromBundle
     NS_ConvertASCIItoUTF16(DEVICESTORAGE_VIDEOS).get(),
     getter_Copies(mVideosExtensions));
 }
 
 
 bool
 DeviceStorageTypeChecker::Check(const nsAString& aType, nsIDOMBlob* aBlob)
 {
-  NS_ASSERTION(aBlob, "Calling Check without a blob");
+  MOZ_ASSERT(aBlob);
 
   nsString mimeType;
   if (NS_FAILED(aBlob->GetType(mimeType))) {
     return false;
   }
 
   if (aType.EqualsLiteral(DEVICESTORAGE_PICTURES)) {
     return StringBeginsWith(mimeType, NS_LITERAL_STRING("image/"));
@@ -276,17 +279,17 @@ DeviceStorageTypeChecker::Check(const ns
   }
 
   return false;
 }
 
 bool
 DeviceStorageTypeChecker::Check(const nsAString& aType, nsIFile* aFile)
 {
-  NS_ASSERTION(aFile, "Calling Check without a file");
+  MOZ_ASSERT(aFile);
 
   if (aType.EqualsLiteral(DEVICESTORAGE_APPS) ||
       aType.EqualsLiteral(DEVICESTORAGE_SDCARD) ||
       aType.EqualsLiteral(DEVICESTORAGE_CRASHES)) {
     // Apps, crashes and sdcard have no restrictions on what file extensions used.
     return true;
   }
 
@@ -316,17 +319,17 @@ DeviceStorageTypeChecker::Check(const ns
   }
 
   return false;
 }
 
 void
 DeviceStorageTypeChecker::GetTypeFromFile(nsIFile* aFile, nsAString& aType)
 {
-  NS_ASSERTION(aFile, "Calling Check without a file");
+  MOZ_ASSERT(aFile);
 
   nsString path;
   aFile->GetPath(path);
 
   GetTypeFromFileName(path, aType);
 }
 
 void
@@ -389,16 +392,17 @@ DeviceStorageTypeChecker::GetAccessForRe
       aAccessResult.AssignLiteral("read");
       break;
     case DEVICE_STORAGE_REQUEST_WRITE:
     case DEVICE_STORAGE_REQUEST_DELETE:
     case DEVICE_STORAGE_REQUEST_FORMAT:
       aAccessResult.AssignLiteral("write");
       break;
     case DEVICE_STORAGE_REQUEST_CREATE:
+    case DEVICE_STORAGE_REQUEST_CREATEFD:
       aAccessResult.AssignLiteral("create");
       break;
     default:
       aAccessResult.AssignLiteral("undefined");
   }
   return NS_OK;
 }
 
@@ -478,17 +482,17 @@ public:
     nsString data;
     CopyASCIItoUTF16(mType, data);
     nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();
 
     obs->NotifyObservers(mFile, "file-watcher-notify", data.get());
 
     DeviceStorageUsedSpaceCache* usedSpaceCache
       = DeviceStorageUsedSpaceCache::CreateOrGet();
-    NS_ASSERTION(usedSpaceCache, "DeviceStorageUsedSpaceCache is null");
+    MOZ_ASSERT(usedSpaceCache);
     usedSpaceCache->Invalidate(mFile->mStorageName);
     return NS_OK;
   }
 
 private:
   nsRefPtr<DeviceStorageFile> mFile;
   nsCString mType;
 };
@@ -569,17 +573,17 @@ void
 DeviceStorageFile::Init()
 {
   DeviceStorageFile::GetRootDirectoryForType(mStorageType,
                                              mStorageName,
                                              getter_AddRefs(mFile));
 
   DebugOnly<DeviceStorageTypeChecker*> typeChecker
     = DeviceStorageTypeChecker::CreateOrGet();
-  NS_ASSERTION(typeChecker, "DeviceStorageTypeChecker is null");
+  MOZ_ASSERT(typeChecker);
 }
 
 // Directories which don't depend on a volume should be calculated once
 // here. Directories which depend on the root directory of a volume
 // should be calculated in DeviceStorageFile::GetRootDirectoryForType.
 static void
 InitDirs()
 {
@@ -587,17 +591,17 @@ InitDirs()
     return;
   }
   MOZ_ASSERT(NS_IsMainThread());
   sDirs = new GlobalDirs;
   ClearOnShutdown(&sDirs);
 
   nsCOMPtr<nsIProperties> dirService
     = do_GetService(NS_DIRECTORY_SERVICE_CONTRACTID);
-  NS_ASSERTION(dirService, "Must have directory service");
+  MOZ_ASSERT(dirService);
 
 #if !defined(MOZ_WIDGET_GONK)
 
 #if defined (MOZ_WIDGET_COCOA)
   dirService->Get(NS_OSX_PICTURE_DOCUMENTS_DIR,
                   NS_GET_IID(nsIFile),
                   getter_AddRefs(sDirs->pictures));
   dirService->Get(NS_OSX_MOVIE_DOCUMENTS_DIR,
@@ -784,17 +788,17 @@ DeviceStorageFile::GetRootDirectoryForTy
 //static
 already_AddRefed<DeviceStorageFile>
 DeviceStorageFile::CreateUnique(nsAString& aFileName,
                                 uint32_t aFileType,
                                 uint32_t aFileAttributes)
 {
   DeviceStorageTypeChecker* typeChecker
     = DeviceStorageTypeChecker::CreateOrGet();
-  NS_ASSERTION(typeChecker, "DeviceStorageTypeChecker is null");
+  MOZ_ASSERT(typeChecker);
 
   nsString storageType;
   typeChecker->GetTypeFromFileName(aFileName, storageType);
 
   nsString storageName;
   nsString storagePath;
   if (!nsDOMDeviceStorage::ParseFullPath(aFileName, storageName, storagePath)) {
     return nullptr;
@@ -919,29 +923,46 @@ DeviceStorageFile::AppendRelativePath(co
   }
   mFile->AppendRelativePath(temp);
 #else
   mFile->AppendRelativePath(aPath);
 #endif
 }
 
 nsresult
+DeviceStorageFile::CreateFileDescriptor(FileDescriptor& aFileDescriptor)
+{
+  PRFileDesc* fd;
+  nsresult rv = mFile->OpenNSPRFileDesc(PR_RDWR | PR_CREATE_FILE,
+                                        0660, &fd);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  aFileDescriptor =
+    FileDescriptor::PlatformHandleType(PR_FileDesc2NativeHandle(fd));
+
+  return NS_OK;
+}
+
+nsresult
 DeviceStorageFile::Write(nsIInputStream* aInputStream)
 {
   if (!aInputStream || !mFile) {
     return NS_ERROR_FAILURE;
   }
 
   nsresult rv = mFile->Create(nsIFile::NORMAL_FILE_TYPE, 00600);
-  if (NS_FAILED(rv)) {
+  if (NS_WARN_IF(NS_FAILED(rv))) {
     return rv;
   }
 
   nsCOMPtr<IOEventComplete> iocomplete = new IOEventComplete(this, "created");
-  NS_DispatchToMainThread(iocomplete);
+  rv = NS_DispatchToMainThread(iocomplete);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
 
   uint64_t bufSize = 0;
   aInputStream->Available(&bufSize);
 
   nsCOMPtr<nsIOutputStream> outputStream;
   NS_NewLocalFileOutputStream(getter_AddRefs(outputStream), mFile);
 
   if (!outputStream) {
@@ -962,54 +983,63 @@ DeviceStorageFile::Write(nsIInputStream*
       &wrote);
     if (NS_FAILED(rv)) {
       break;
     }
     bufSize -= wrote;
   }
 
   iocomplete = new IOEventComplete(this, "modified");
-  NS_DispatchToMainThread(iocomplete);
+  rv = NS_DispatchToMainThread(iocomplete);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
 
   bufferedOutputStream->Close();
   outputStream->Close();
-  if (NS_FAILED(rv)) {
+  if (NS_WARN_IF(NS_FAILED(rv))) {
     return rv;
   }
   return NS_OK;
 }
 
 nsresult
 DeviceStorageFile::Write(InfallibleTArray<uint8_t>& aBits)
 {
   if (!mFile) {
     return NS_ERROR_FAILURE;
   }
 
   nsresult rv = mFile->Create(nsIFile::NORMAL_FILE_TYPE, 00600);
-  if (NS_FAILED(rv)) {
+  if (NS_WARN_IF(NS_FAILED(rv))) {
     return rv;
   }
 
   nsCOMPtr<IOEventComplete> iocomplete = new IOEventComplete(this, "created");
-  NS_DispatchToMainThread(iocomplete);
+  rv = NS_DispatchToMainThread(iocomplete);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
 
   nsCOMPtr<nsIOutputStream> outputStream;
   NS_NewLocalFileOutputStream(getter_AddRefs(outputStream), mFile);
 
   if (!outputStream) {
     return NS_ERROR_FAILURE;
   }
 
   uint32_t wrote;
   outputStream->Write((char*) aBits.Elements(), aBits.Length(), &wrote);
   outputStream->Close();
 
   iocomplete = new IOEventComplete(this, "modified");
-  NS_DispatchToMainThread(iocomplete);
+  rv = NS_DispatchToMainThread(iocomplete);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
 
   if (aBits.Length() != wrote) {
     return NS_ERROR_FAILURE;
   }
   return NS_OK;
 }
 
 nsresult
@@ -1027,23 +1057,22 @@ DeviceStorageFile::Remove()
     return rv;
   }
 
   if (!check) {
     return NS_OK;
   }
 
   rv = mFile->Remove(true);
-  if (NS_FAILED(rv)) {
+  if (NS_WARN_IF(NS_FAILED(rv))) {
     return rv;
   }
 
   nsCOMPtr<IOEventComplete> iocomplete = new IOEventComplete(this, "deleted");
-  NS_DispatchToMainThread(iocomplete);
-  return NS_OK;
+  return NS_DispatchToMainThread(iocomplete);
 }
 
 nsresult
 DeviceStorageFile::CalculateMimeType()
 {
   MOZ_ASSERT(NS_IsMainThread());
 
   nsAutoCString mimeType;
@@ -1111,17 +1140,17 @@ DeviceStorageFile::collectFilesInternal(
 
   while (NS_SUCCEEDED(files->GetNextFile(getter_AddRefs(f))) && f) {
 
     PRTime msecs;
     f->GetLastModifiedTime(&msecs);
 
     if (msecs < aSince) {
       continue;
-     }
+    }
 
     bool isDir;
     f->IsDirectory(&isDir);
 
     bool isFile;
     f->IsFile(&isFile);
 
     nsString fullpath;
@@ -1160,17 +1189,17 @@ DeviceStorageFile::AccumDiskUsage(uint64
     return;
   }
 
   uint64_t pictureUsage = 0, videoUsage = 0, musicUsage = 0, totalUsage = 0;
 
   if (DeviceStorageTypeChecker::IsVolumeBased(mStorageType)) {
     DeviceStorageUsedSpaceCache* usedSpaceCache =
       DeviceStorageUsedSpaceCache::CreateOrGet();
-    NS_ASSERTION(usedSpaceCache, "DeviceStorageUsedSpaceCache is null");
+    MOZ_ASSERT(usedSpaceCache);
     nsresult rv = usedSpaceCache->AccumUsedSizes(mStorageName,
                                                  aPicturesSoFar, aVideosSoFar,
                                                  aMusicSoFar, aTotalSoFar);
     if (NS_SUCCEEDED(rv)) {
       return;
     }
     AccumDirectoryUsage(mFile, &pictureUsage, &videoUsage,
                         &musicUsage, &totalUsage);
@@ -1202,18 +1231,17 @@ DeviceStorageFile::AccumDirectoryUsage(n
   nsCOMPtr<nsISimpleEnumerator> e;
   rv = aFile->GetDirectoryEntries(getter_AddRefs(e));
 
   if (NS_FAILED(rv) || !e) {
     return;
   }
 
   nsCOMPtr<nsIDirectoryEnumerator> files = do_QueryInterface(e);
-  NS_ASSERTION(files,
-               "GetDirectoryEntries must return a nsIDirectoryEnumerator");
+  MOZ_ASSERT(files);
 
   nsCOMPtr<nsIFile> f;
   while (NS_SUCCEEDED(files->GetNextFile(getter_AddRefs(f))) && f) {
     bool isDir;
     rv = f->IsDirectory(&isDir);
     if (NS_FAILED(rv)) {
       continue;
     }
@@ -1240,17 +1268,17 @@ DeviceStorageFile::AccumDirectoryUsage(n
 
       int64_t size;
       rv = f->GetFileSize(&size);
       if (NS_FAILED(rv)) {
         continue;
       }
       DeviceStorageTypeChecker* typeChecker
         = DeviceStorageTypeChecker::CreateOrGet();
-      NS_ASSERTION(typeChecker, "DeviceStorageTypeChecker is null");
+      MOZ_ASSERT(typeChecker);
       nsString type;
       typeChecker->GetTypeFromFile(f, type);
 
       if (type.EqualsLiteral(DEVICESTORAGE_PICTURES)) {
         *aPicturesSoFar += size;
       }
       else if (type.EqualsLiteral(DEVICESTORAGE_VIDEOS)) {
         *aVideosSoFar += size;
@@ -1436,47 +1464,46 @@ InterfaceToJsval(nsPIDOMWindow* aWindow,
 
   return someJsVal;
 }
 
 JS::Value
 nsIFileToJsval(nsPIDOMWindow* aWindow, DeviceStorageFile* aFile)
 {
   MOZ_ASSERT(NS_IsMainThread());
-  NS_ASSERTION(aWindow, "Null Window");
+  MOZ_ASSERT(aWindow);
 
   if (!aFile) {
     return JSVAL_NULL;
   }
 
   if (aFile->mEditable) {
     // TODO - needs janv's file handle support.
     return JSVAL_NULL;
   }
 
   nsString fullPath;
   aFile->GetFullPath(fullPath);
 
   // This check is useful to know if somewhere the DeviceStorageFile
   // has not been properly set. Mimetype is not checked because it can be
   // empty.
-  NS_ASSERTION(aFile->mLength != UINT64_MAX, "Size not set");
-  NS_ASSERTION(aFile->mLastModifiedDate != UINT64_MAX,
-               "LastModifiedDate not set");
+  MOZ_ASSERT(aFile->mLength != UINT64_MAX);
+  MOZ_ASSERT(aFile->mLastModifiedDate != UINT64_MAX);
 
   nsCOMPtr<nsIDOMBlob> blob = new nsDOMFileFile(fullPath, aFile->mMimeType,
                                                 aFile->mLength, aFile->mFile,
                                                 aFile->mLastModifiedDate);
   return InterfaceToJsval(aWindow, blob, &NS_GET_IID(nsIDOMBlob));
 }
 
 JS::Value StringToJsval(nsPIDOMWindow* aWindow, nsAString& aString)
 {
   MOZ_ASSERT(NS_IsMainThread());
-  NS_ASSERTION(aWindow, "Null Window");
+  MOZ_ASSERT(aWindow);
 
   nsCOMPtr<nsIScriptGlobalObject> sgo = do_QueryInterface(aWindow);
   if (!sgo) {
     return JSVAL_NULL;
   }
 
   nsIScriptContext *scriptContext = sgo->GetScriptContext();
   if (!scriptContext) {
@@ -1615,25 +1642,27 @@ ContinueCursorEvent::GetNextFile()
 }
 
 ContinueCursorEvent::~ContinueCursorEvent() {}
 
 void
 ContinueCursorEvent::Continue()
 {
   if (XRE_GetProcessType() == GeckoProcessType_Default) {
-    NS_DispatchToMainThread(this);
+    DebugOnly<nsresult> rv = NS_DispatchToMainThread(this);
+    MOZ_ASSERT(NS_SUCCEEDED(rv));
     return;
   }
 
   nsRefPtr<DeviceStorageFile> file = GetNextFile();
 
   if (!file) {
     // done with enumeration.
-    NS_DispatchToMainThread(this);
+    DebugOnly<nsresult> rv = NS_DispatchToMainThread(this);
+    MOZ_ASSERT(NS_SUCCEEDED(rv));
     return;
   }
 
   nsDOMDeviceStorageCursor* cursor
     = static_cast<nsDOMDeviceStorageCursor*>(mRequest.get());
   nsString cursorStorageType;
   cursor->GetStorageType(cursorStorageType);
 
@@ -1686,18 +1715,17 @@ public:
 
     if (mFile->mFile) {
       bool check;
       mFile->mFile->IsDirectory(&check);
       if (!check) {
         nsCOMPtr<PostErrorEvent> event =
           new PostErrorEvent(mRequest.forget(),
                              POST_ERROR_EVENT_FILE_NOT_ENUMERABLE);
-        NS_DispatchToMainThread(event);
-        return NS_OK;
+        return NS_DispatchToMainThread(event);
       }
     }
 
     nsDOMDeviceStorageCursor* cursor
       = static_cast<nsDOMDeviceStorageCursor*>(mRequest.get());
     mFile->CollectFiles(cursor->mFiles, cursor->mSince);
 
     nsCOMPtr<ContinueCursorEvent> event
@@ -1777,45 +1805,43 @@ nsDOMDeviceStorageCursor::GetElement(nsI
   return NS_OK;
 }
 
 NS_IMETHODIMP
 nsDOMDeviceStorageCursor::Cancel()
 {
   nsCOMPtr<PostErrorEvent> event
     = new PostErrorEvent(this, POST_ERROR_EVENT_PERMISSION_DENIED);
-  NS_DispatchToMainThread(event);
-  return NS_OK;
+  return NS_DispatchToMainThread(event);
 }
 
 NS_IMETHODIMP
 nsDOMDeviceStorageCursor::Allow()
 {
   if (!mFile->IsSafePath()) {
     nsCOMPtr<nsIRunnable> r
       = new PostErrorEvent(this, POST_ERROR_EVENT_PERMISSION_DENIED);
-    NS_DispatchToMainThread(r);
-    return NS_OK;
+    return NS_DispatchToMainThread(r);
   }
 
   if (XRE_GetProcessType() != GeckoProcessType_Default) {
     PDeviceStorageRequestChild* child
       = new DeviceStorageRequestChild(this, mFile);
     DeviceStorageEnumerationParams params(mFile->mStorageType,
                                           mFile->mStorageName,
                                           mFile->mRootDir,
                                           mSince);
     ContentChild::GetSingleton()->SendPDeviceStorageRequestConstructor(child,
                                                                        params);
     return NS_OK;
   }
 
   nsCOMPtr<nsIEventTarget> target
     = do_GetService(NS_STREAMTRANSPORTSERVICE_CONTRACTID);
-  NS_ASSERTION(target, "Must have stream transport service");
+  MOZ_ASSERT(target);
 
   nsCOMPtr<InitCursorEvent> event = new InitCursorEvent(this, mFile);
   target->Dispatch(event, NS_DISPATCH_NORMAL);
   return NS_OK;
 }
 
 void
 nsDOMDeviceStorageCursor::Continue(ErrorResult& aRv)
@@ -1854,27 +1880,28 @@ void
 nsDOMDeviceStorageCursor::IPDLRelease()
 {
   Release();
 }
 
 void
 nsDOMDeviceStorageCursor::RequestComplete()
 {
-  NS_ASSERTION(!mOkToCallContinue, "mOkToCallContinue must be false");
+  MOZ_ASSERT(!mOkToCallContinue);
   mOkToCallContinue = true;
 }
 
 class PostAvailableResultEvent : public nsRunnable
 {
 public:
   PostAvailableResultEvent(DeviceStorageFile *aFile, DOMRequest* aRequest)
     : mFile(aFile)
     , mRequest(aRequest)
   {
+    MOZ_ASSERT(mRequest);
   }
 
   ~PostAvailableResultEvent() {}
 
   NS_IMETHOD Run()
   {
     MOZ_ASSERT(NS_IsMainThread());
 
@@ -1898,16 +1925,17 @@ private:
 
 class PostFormatResultEvent : public nsRunnable
 {
 public:
   PostFormatResultEvent(DeviceStorageFile *aFile, DOMRequest* aRequest)
     : mFile(aFile)
     , mRequest(aRequest)
   {
+    MOZ_ASSERT(mRequest);
   }
 
   ~PostFormatResultEvent() {}
 
   NS_IMETHOD Run()
   {
     MOZ_ASSERT(NS_IsMainThread());
 
@@ -1931,29 +1959,35 @@ private:
 
 class PostResultEvent : public nsRunnable
 {
 public:
   PostResultEvent(already_AddRefed<DOMRequest> aRequest,
                   DeviceStorageFile* aFile)
     : mFile(aFile)
     , mRequest(aRequest)
-  {}
+  {
+    MOZ_ASSERT(mRequest);
+  }
 
   PostResultEvent(already_AddRefed<DOMRequest> aRequest,
                   const nsAString & aPath)
     : mPath(aPath)
     , mRequest(aRequest)
-  {}
+  {
+    MOZ_ASSERT(mRequest);
+  }
 
   PostResultEvent(already_AddRefed<DOMRequest> aRequest,
                   const uint64_t aValue)
     : mValue(aValue)
     , mRequest(aRequest)
-  {}
+  {
+    MOZ_ASSERT(mRequest);
+  }
 
   ~PostResultEvent() {}
 
   NS_IMETHOD Run()
   {
     MOZ_ASSERT(NS_IsMainThread());
 
     AutoJSContext cx;
@@ -1976,78 +2010,131 @@ public:
 
 private:
   nsRefPtr<DeviceStorageFile> mFile;
   nsString mPath;
   uint64_t mValue;
   nsRefPtr<DOMRequest> mRequest;
 };
 
+class CreateFdEvent : public nsRunnable
+{
+public:
+  CreateFdEvent(DeviceStorageFileDescriptor* aDSFileDescriptor,
+                already_AddRefed<DOMRequest> aRequest)
+    : mDSFileDescriptor(aDSFileDescriptor)
+    , mRequest(aRequest)
+  {
+    MOZ_ASSERT(mDSFileDescriptor);
+    MOZ_ASSERT(mRequest);
+  }
+
+  NS_IMETHOD Run()
+  {
+    MOZ_ASSERT(!NS_IsMainThread());
+
+    DeviceStorageFile* dsFile = mDSFileDescriptor->mDSFile;
+    MOZ_ASSERT(dsFile);
+
+    nsString fullPath;
+    dsFile->GetFullPath(fullPath);
+    MOZ_ASSERT(!fullPath.IsEmpty());
+
+    bool check = false;
+    dsFile->mFile->Exists(&check);
+    if (check) {
+      nsCOMPtr<PostErrorEvent> event =
+        new PostErrorEvent(mRequest.forget(), POST_ERROR_EVENT_FILE_EXISTS);
+      return NS_DispatchToMainThread(event);
+    }
+
+    nsresult rv = dsFile->CreateFileDescriptor(mDSFileDescriptor->mFileDescriptor);
+
+    if (NS_FAILED(rv)) {
+      dsFile->mFile->Remove(false);
+
+      nsCOMPtr<PostErrorEvent> event =
+        new PostErrorEvent(mRequest.forget(), POST_ERROR_EVENT_UNKNOWN);
+      return NS_DispatchToMainThread(event);
+    }
+
+    nsCOMPtr<PostResultEvent> event =
+      new PostResultEvent(mRequest.forget(), fullPath);
+    return NS_DispatchToMainThread(event);
+  }
+
+private:
+  nsRefPtr<DeviceStorageFileDescriptor> mDSFileDescriptor;
+  nsRefPtr<DOMRequest> mRequest;
+};
+
 class WriteFileEvent : public nsRunnable
 {
 public:
   WriteFileEvent(nsIDOMBlob* aBlob,
                  DeviceStorageFile *aFile,
                  already_AddRefed<DOMRequest> aRequest)
     : mBlob(aBlob)
     , mFile(aFile)
     , mRequest(aRequest)
-  {}
+  {
+    MOZ_ASSERT(mFile);
+    MOZ_ASSERT(mRequest);
+  }
 
   ~WriteFileEvent() {}
 
   NS_IMETHOD Run()
   {
     MOZ_ASSERT(!NS_IsMainThread());
 
     nsCOMPtr<nsIInputStream> stream;
     mBlob->GetInternalStream(getter_AddRefs(stream));
 
     bool check = false;
     mFile->mFile->Exists(&check);
     if (check) {
       nsCOMPtr<PostErrorEvent> event =
         new PostErrorEvent(mRequest.forget(), POST_ERROR_EVENT_FILE_EXISTS);
-      NS_DispatchToMainThread(event);
-      return NS_OK;
+      return NS_DispatchToMainThread(event);
     }
 
     nsresult rv = mFile->Write(stream);
 
     if (NS_FAILED(rv)) {
       mFile->mFile->Remove(false);
 
       nsCOMPtr<PostErrorEvent> event =
         new PostErrorEvent(mRequest.forget(), POST_ERROR_EVENT_UNKNOWN);
-      NS_DispatchToMainThread(event);
-      return NS_OK;
+      return NS_DispatchToMainThread(event);
     }
 
     nsString fullPath;
     mFile->GetFullPath(fullPath);
     nsCOMPtr<PostResultEvent> event =
       new PostResultEvent(mRequest.forget(), fullPath);
-    NS_DispatchToMainThread(event);
-    return NS_OK;
+    return NS_DispatchToMainThread(event);
   }
 
 private:
   nsCOMPtr<nsIDOMBlob> mBlob;
   nsRefPtr<DeviceStorageFile> mFile;
   nsRefPtr<DOMRequest> mRequest;
 };
 
 class ReadFileEvent : public nsRunnable
 {
 public:
   ReadFileEvent(DeviceStorageFile* aFile,
                 already_AddRefed<DOMRequest> aRequest)
     : mFile(aFile)
     , mRequest(aRequest)
   {
+    MOZ_ASSERT(mFile);
+    MOZ_ASSERT(mRequest);
     mFile->CalculateMimeType();
   }
 
   ~ReadFileEvent() {}
 
   NS_IMETHOD Run()
   {
     MOZ_ASSERT(!NS_IsMainThread());
@@ -2067,33 +2154,35 @@ public:
       if (NS_FAILED(rv)) {
         r = new PostErrorEvent(mRequest.forget(), POST_ERROR_EVENT_UNKNOWN);
       }
     }
 
     if (!r) {
       r = new PostResultEvent(mRequest.forget(), mFile);
     }
-    NS_DispatchToMainThread(r);
-    return NS_OK;
+    return NS_DispatchToMainThread(r);
   }
 
 private:
   nsRefPtr<DeviceStorageFile> mFile;
   nsRefPtr<DOMRequest> mRequest;
 };
 
 class DeleteFileEvent : public nsRunnable
 {
 public:
   DeleteFileEvent(DeviceStorageFile* aFile,
                   already_AddRefed<DOMRequest> aRequest)
     : mFile(aFile)
     , mRequest(aRequest)
-  {}
+  {
+    MOZ_ASSERT(mFile);
+    MOZ_ASSERT(mRequest);
+  }
 
   ~DeleteFileEvent() {}
 
   NS_IMETHOD Run()
   {
     MOZ_ASSERT(!NS_IsMainThread());
     mFile->Remove();
 
@@ -2104,33 +2193,35 @@ public:
       r = new PostErrorEvent(mRequest.forget(),
                              POST_ERROR_EVENT_FILE_DOES_NOT_EXIST);
     }
     else {
       nsString fullPath;
       mFile->GetFullPath(fullPath);
       r = new PostResultEvent(mRequest.forget(), fullPath);
     }
-    NS_DispatchToMainThread(r);
-    return NS_OK;
+    return NS_DispatchToMainThread(r);
   }
 
 private:
   nsRefPtr<DeviceStorageFile> mFile;
   nsRefPtr<DOMRequest> mRequest;
 };
 
 class UsedSpaceFileEvent : public nsRunnable
 {
 public:
   UsedSpaceFileEvent(DeviceStorageFile* aFile,
                      already_AddRefed<DOMRequest> aRequest)
     : mFile(aFile)
     , mRequest(aRequest)
-  {}
+  {
+    MOZ_ASSERT(mFile);
+    MOZ_ASSERT(mRequest);
+  }
 
   ~UsedSpaceFileEvent() {}
 
   NS_IMETHOD Run()
   {
     MOZ_ASSERT(!NS_IsMainThread());
 
     uint64_t picturesUsage = 0, videosUsage = 0, musicUsage = 0, totalUsage = 0;
@@ -2143,90 +2234,124 @@ public:
     else if (mFile->mStorageType.EqualsLiteral(DEVICESTORAGE_VIDEOS)) {
       r = new PostResultEvent(mRequest.forget(), videosUsage);
     }
     else if (mFile->mStorageType.EqualsLiteral(DEVICESTORAGE_MUSIC)) {
       r = new PostResultEvent(mRequest.forget(), musicUsage);
     } else {
       r = new PostResultEvent(mRequest.forget(), totalUsage);
     }
-    NS_DispatchToMainThread(r);
-    return NS_OK;
+    return NS_DispatchToMainThread(r);
   }
 
 private:
   nsRefPtr<DeviceStorageFile> mFile;
   nsRefPtr<DOMRequest> mRequest;
 };
 
 class FreeSpaceFileEvent : public nsRunnable
 {
 public:
   FreeSpaceFileEvent(DeviceStorageFile* aFile,
                      already_AddRefed<DOMRequest> aRequest)
     : mFile(aFile)
     , mRequest(aRequest)
-  {}
+  {
+    MOZ_ASSERT(mFile);
+    MOZ_ASSERT(mRequest);
+  }
 
   ~FreeSpaceFileEvent() {}
 
   NS_IMETHOD Run()
   {
     MOZ_ASSERT(!NS_IsMainThread());
 
     int64_t freeSpace = 0;
     if (mFile) {
       mFile->GetDiskFreeSpace(&freeSpace);
     }
 
     nsCOMPtr<nsIRunnable> r;
     r = new PostResultEvent(mRequest.forget(),
                             static_cast<uint64_t>(freeSpace));
-    NS_DispatchToMainThread(r);
-    return NS_OK;
+    return NS_DispatchToMainThread(r);
   }
 
 private:
   nsRefPtr<DeviceStorageFile> mFile;
   nsRefPtr<DOMRequest> mRequest;
 };
 
 class DeviceStorageRequest MOZ_FINAL
   : public nsIContentPermissionRequest
   , public nsIRunnable
   , public PCOMContentPermissionRequestChild
 {
 public:
 
-    DeviceStorageRequest(const DeviceStorageRequestType aRequestType,
-                         nsPIDOMWindow *aWindow,
-                         nsIPrincipal *aPrincipal,
-                         DeviceStorageFile *aFile,
-                         DOMRequest* aRequest,
-                         nsDOMDeviceStorage *aDeviceStorage)
-      : mRequestType(aRequestType)
-      , mWindow(aWindow)
-      , mPrincipal(aPrincipal)
-      , mFile(aFile)
-      , mRequest(aRequest)
-      , mDeviceStorage(aDeviceStorage)
-    {}
-
-    DeviceStorageRequest(const DeviceStorageRequestType aRequestType,
-                         nsPIDOMWindow *aWindow,
-                         nsIPrincipal *aPrincipal,
-                         DeviceStorageFile *aFile,
-                         DOMRequest* aRequest,
-                         nsIDOMBlob *aBlob = nullptr)
-      : mRequestType(aRequestType)
-      , mWindow(aWindow)
-      , mPrincipal(aPrincipal)
-      , mFile(aFile)
-      , mRequest(aRequest)
-      , mBlob(aBlob) {}
+  DeviceStorageRequest(const DeviceStorageRequestType aRequestType,
+                       nsPIDOMWindow* aWindow,
+                       nsIPrincipal* aPrincipal,
+                       DeviceStorageFile* aFile,
+                       DOMRequest* aRequest,
+                       nsDOMDeviceStorage* aDeviceStorage)
+    : mRequestType(aRequestType)
+    , mWindow(aWindow)
+    , mPrincipal(aPrincipal)
+    , mFile(aFile)
+    , mRequest(aRequest)
+    , mDeviceStorage(aDeviceStorage)
+  {
+    MOZ_ASSERT(mWindow);
+    MOZ_ASSERT(mPrincipal);
+    MOZ_ASSERT(mFile);
+    MOZ_ASSERT(mRequest);
+    MOZ_ASSERT(mDeviceStorage);
+  }
+
+  DeviceStorageRequest(const DeviceStorageRequestType aRequestType,
+                       nsPIDOMWindow* aWindow,
+                       nsIPrincipal* aPrincipal,
+                       DeviceStorageFile* aFile,
+                       DOMRequest* aRequest,
+                       nsIDOMBlob* aBlob = nullptr)
+    : mRequestType(aRequestType)
+    , mWindow(aWindow)
+    , mPrincipal(aPrincipal)
+    , mFile(aFile)
+    , mRequest(aRequest)
+    , mBlob(aBlob)
+  {
+    MOZ_ASSERT(mWindow);
+    MOZ_ASSERT(mPrincipal);
+    MOZ_ASSERT(mFile);
+    MOZ_ASSERT(mRequest);
+  }
+
+  DeviceStorageRequest(const DeviceStorageRequestType aRequestType,
+                       nsPIDOMWindow* aWindow,
+                       nsIPrincipal* aPrincipal,
+                       DeviceStorageFile* aFile,
+                       DOMRequest* aRequest,
+                       DeviceStorageFileDescriptor* aDSFileDescriptor)
+    : mRequestType(aRequestType)
+    , mWindow(aWindow)
+    , mPrincipal(aPrincipal)
+    , mFile(aFile)
+    , mRequest(aRequest)
+    , mDSFileDescriptor(aDSFileDescriptor)
+  {
+    MOZ_ASSERT(mRequestType == DEVICE_STORAGE_REQUEST_CREATEFD);
+    MOZ_ASSERT(mWindow);
+    MOZ_ASSERT(mPrincipal);
+    MOZ_ASSERT(mFile);
+    MOZ_ASSERT(mRequest);
+    MOZ_ASSERT(mDSFileDescriptor);
+  }
 
   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
   NS_DECL_CYCLE_COLLECTION_CLASS_AMBIGUOUS(DeviceStorageRequest,
                                            nsIContentPermissionRequest)
 
   NS_IMETHOD Run() {
     MOZ_ASSERT(NS_IsMainThread());
 
@@ -2316,51 +2441,89 @@ public:
     return NS_OK;
   }
 
   NS_IMETHOD Cancel()
   {
     nsCOMPtr<PostErrorEvent> event
       = new PostErrorEvent(mRequest.forget(),
                            POST_ERROR_EVENT_PERMISSION_DENIED);
-    NS_DispatchToMainThread(event);
-    return NS_OK;
+    return NS_DispatchToMainThread(event);
   }
 
   NS_IMETHOD Allow()
   {
-    nsCOMPtr<nsIRunnable> r;
+    MOZ_ASSERT(NS_IsMainThread());
 
     if (!mRequest) {
       return NS_ERROR_FAILURE;
     }
 
+    nsCOMPtr<nsIRunnable> r;
+
     switch(mRequestType) {
+      case DEVICE_STORAGE_REQUEST_CREATEFD:
+      {
+        if (!mFile->mFile) {
+          return NS_ERROR_FAILURE;
+        }
+
+        DeviceStorageTypeChecker* typeChecker
+          = DeviceStorageTypeChecker::CreateOrGet();
+        if (!typeChecker) {
+          return NS_OK;
+        }
+
+        if (!typeChecker->Check(mFile->mStorageType, mFile->mFile)) {
+          r = new PostErrorEvent(mRequest.forget(),
+                                 POST_ERROR_EVENT_ILLEGAL_TYPE);
+          return NS_DispatchToCurrentThread(r);
+        }
+
+        if (XRE_GetProcessType() != GeckoProcessType_Default) {
+
+          DeviceStorageCreateFdParams params;
+          params.type() = mFile->mStorageType;
+          params.storageName() = mFile->mStorageName;
+          params.relpath() = mFile->mPath;
+
+          mFile->Dump("DeviceStorageCreateFdParams");
+
+          PDeviceStorageRequestChild* child
+            = new DeviceStorageRequestChild(mRequest, mFile,
+                                            mDSFileDescriptor.get());
+          ContentChild::GetSingleton()
+            ->SendPDeviceStorageRequestConstructor(child, params);
+          return NS_OK;
+        }
+        mDSFileDescriptor->mDSFile = mFile;
+        r = new CreateFdEvent(mDSFileDescriptor.get(), mRequest.forget());
+        break;
+      }
+
       case DEVICE_STORAGE_REQUEST_CREATE:
       {
         if (!mBlob || !mFile->mFile) {
           return NS_ERROR_FAILURE;
         }
 
         DeviceStorageTypeChecker* typeChecker
           = DeviceStorageTypeChecker::CreateOrGet();
         if (!typeChecker) {
           return NS_OK;
         }
 
         if (!typeChecker->Check(mFile->mStorageType, mFile->mFile) ||
             !typeChecker->Check(mFile->mStorageType, mBlob)) {
           r = new PostErrorEvent(mRequest.forget(),
                                  POST_ERROR_EVENT_ILLEGAL_TYPE);
-          NS_DispatchToMainThread(r);
-          return NS_OK;
+          return NS_DispatchToCurrentThread(r);
         }
 
         if (XRE_GetProcessType() != GeckoProcessType_Default) {
-
           BlobChild* actor
             = ContentChild::GetSingleton()->GetOrCreateActorForBlob(mBlob);
           if (!actor) {
             return NS_ERROR_FAILURE;
           }
 
           DeviceStorageAddParams params;
           params.blobChild() = actor;
@@ -2389,18 +2552,17 @@ public:
           = DeviceStorageTypeChecker::CreateOrGet();
         if (!typeChecker) {
           return NS_OK;
         }
 
         if (!typeChecker->Check(mFile->mStorageType, mFile->mFile)) {
           r = new PostErrorEvent(mRequest.forget(),
                                  POST_ERROR_EVENT_ILLEGAL_TYPE);
-          NS_DispatchToMainThread(r);
-          return NS_OK;
+          return NS_DispatchToCurrentThread(r);
         }
 
         if (XRE_GetProcessType() != GeckoProcessType_Default) {
           PDeviceStorageRequestChild* child
             = new DeviceStorageRequestChild(mRequest, mFile);
           DeviceStorageGetParams params(mFile->mStorageType,
                                         mFile->mStorageName,
                                         mFile->mRootDir,
@@ -2424,18 +2586,17 @@ public:
           = DeviceStorageTypeChecker::CreateOrGet();
         if (!typeChecker) {
           return NS_OK;
         }
 
         if (!typeChecker->Check(mFile->mStorageType, mFile->mFile)) {
           r = new PostErrorEvent(mRequest.forget(),
                                  POST_ERROR_EVENT_ILLEGAL_TYPE);
-          NS_DispatchToMainThread(r);
-          return NS_OK;
+          return NS_DispatchToCurrentThread(r);
         }
 
         if (XRE_GetProcessType() != GeckoProcessType_Default) {
           PDeviceStorageRequestChild* child
             = new DeviceStorageRequestChild(mRequest, mFile);
           DeviceStorageDeleteParams params(mFile->mStorageType,
                                            mFile->mStorageName,
                                            mFile->mPath);
@@ -2472,17 +2633,17 @@ public:
           ContentChild::GetSingleton()
             ->SendPDeviceStorageRequestConstructor(child, params);
           return NS_OK;
         }
         // this needs to be dispatched to only one (1)
         // thread or we will do more work than required.
         DeviceStorageUsedSpaceCache* usedSpaceCache
           = DeviceStorageUsedSpaceCache::CreateOrGet();
-        NS_ASSERTION(usedSpaceCache, "DeviceStorageUsedSpaceCache is null");
+        MOZ_ASSERT(usedSpaceCache);
         r = new UsedSpaceFileEvent(mFile, mRequest.forget());
         usedSpaceCache->Dispatch(r);
         return NS_OK;
       }
 
       case DEVICE_STORAGE_REQUEST_AVAILABLE:
       {
         if (XRE_GetProcessType() != GeckoProcessType_Default) {
@@ -2490,18 +2651,17 @@ public:
             = new DeviceStorageRequestChild(mRequest, mFile);
           DeviceStorageAvailableParams params(mFile->mStorageType,
                                               mFile->mStorageName);
           ContentChild::GetSingleton()
             ->SendPDeviceStorageRequestConstructor(child, params);
           return NS_OK;
         }
         r = new PostAvailableResultEvent(mFile, mRequest);
-        NS_DispatchToMainThread(r);
-        return NS_OK;
+        return NS_DispatchToCurrentThread(r);
       }
 
       case DEVICE_STORAGE_REQUEST_WATCH:
       {
         mDeviceStorage->mAllowedToWatchFile = true;
         return NS_OK;
       }
 
@@ -2512,26 +2672,25 @@ public:
             = new DeviceStorageRequestChild(mRequest, mFile);
           DeviceStorageFormatParams params(mFile->mStorageType,
                                            mFile->mStorageName);
           ContentChild::GetSingleton()
             ->SendPDeviceStorageRequestConstructor(child, params);
           return NS_OK;
         }
         r = new PostFormatResultEvent(mFile, mRequest);
-        NS_DispatchToMainThread(r);
-        return NS_OK;
+        return NS_DispatchToCurrentThread(r);
       }
 
     }
 
     if (r) {
       nsCOMPtr<nsIEventTarget> target
         = do_GetService(NS_STREAMTRANSPORTSERVICE_CONTRACTID);
-      NS_ASSERTION(target, "Must have stream transport service");
+      MOZ_ASSERT(target);
       target->Dispatch(r, NS_DISPATCH_NORMAL);
     }
 
     return NS_OK;
   }
 
   bool Recv__delete__(const bool& allow)
   {
@@ -2553,16 +2712,17 @@ private:
   int32_t mRequestType;
   nsCOMPtr<nsPIDOMWindow> mWindow;
   nsCOMPtr<nsIPrincipal> mPrincipal;
   nsRefPtr<DeviceStorageFile> mFile;
 
   nsRefPtr<DOMRequest> mRequest;
   nsCOMPtr<nsIDOMBlob> mBlob;
   nsRefPtr<nsDOMDeviceStorage> mDeviceStorage;
+  nsRefPtr<DeviceStorageFileDescriptor> mDSFileDescriptor;
 };
 
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(DeviceStorageRequest)
   NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIContentPermissionRequest)
   NS_INTERFACE_MAP_ENTRY(nsIContentPermissionRequest)
   NS_INTERFACE_MAP_ENTRY(nsIRunnable)
 NS_INTERFACE_MAP_END
 
@@ -2598,19 +2758,19 @@ nsDOMDeviceStorage::WrapObject(JSContext
 }
 
 nsresult
 nsDOMDeviceStorage::Init(nsPIDOMWindow* aWindow, const nsAString &aType,
                          const nsAString &aVolName)
 {
   DebugOnly<FileUpdateDispatcher*> observer
     = FileUpdateDispatcher::GetSingleton();
-  NS_ASSERTION(observer, "FileUpdateDispatcher is null");
-
-  NS_ASSERTION(aWindow, "Must have a content dom");
+  MOZ_ASSERT(observer);
+
+  MOZ_ASSERT(aWindow);
 
   SetRootDirectoryForType(aType, aVolName);
   if (!mRootDirectory) {
     return NS_ERROR_NOT_AVAILABLE;
   }
   if (!mStorageName.IsEmpty()) {
     RegisterForSDCardChanges(this);
   }
@@ -2794,16 +2954,18 @@ nsDOMDeviceStorage::GetStorage(const nsA
     ds = GetStorageByName(storageName);
   }
   return ds.forget();
 }
 
 already_AddRefed<nsDOMDeviceStorage>
 nsDOMDeviceStorage::GetStorageByName(const nsAString& aStorageName)
 {
+  MOZ_ASSERT(NS_IsMainThread());
+
   nsRefPtr<nsDOMDeviceStorage> ds;
 
   if (mStorageName.Equals(aStorageName)) {
     ds = this;
     return ds.forget();
   }
   VolumeNameArray volNames;
   GetOrderedVolumeNames(volNames);
@@ -2909,16 +3071,18 @@ nsDOMDeviceStorage::AddNamed(nsIDOMBlob 
   request.forget(_retval);
   return rv.ErrorCode();
 }
 
 already_AddRefed<DOMRequest>
 nsDOMDeviceStorage::AddNamed(nsIDOMBlob* aBlob, const nsAString& aPath,
                              ErrorResult& aRv)
 {
+  MOZ_ASSERT(NS_IsMainThread());
+
   // if the blob is null here, bail
   if (!aBlob) {
     return nullptr;
   }
 
   nsCOMPtr<nsPIDOMWindow> win = GetOwner();
   if (!win) {
     aRv.Throw(NS_ERROR_UNEXPECTED);
@@ -2928,24 +3092,28 @@ nsDOMDeviceStorage::AddNamed(nsIDOMBlob*
   DeviceStorageTypeChecker* typeChecker
     = DeviceStorageTypeChecker::CreateOrGet();
   if (!typeChecker) {
     aRv.Throw(NS_ERROR_FAILURE);
     return nullptr;
   }
 
   nsCOMPtr<nsIRunnable> r;
+  nsresult rv;
 
   if (IsFullPath(aPath)) {
     nsString storagePath;
     nsRefPtr<nsDOMDeviceStorage> ds = GetStorage(aPath, storagePath);
     if (!ds) {
       nsRefPtr<DOMRequest> request = new DOMRequest(win);
       r = new PostErrorEvent(request, POST_ERROR_EVENT_UNKNOWN);
-      NS_DispatchToMainThread(r);
+      rv = NS_DispatchToCurrentThread(r);
+      if (NS_FAILED(rv)) {
+        aRv.Throw(rv);
+      }
       return request.forget();
     }
     return ds->AddNamed(aBlob, storagePath, aRv);
   }
 
   nsRefPtr<DOMRequest> request = new DOMRequest(win);
 
   nsRefPtr<DeviceStorageFile> dsf = new DeviceStorageFile(mStorageType,
@@ -2956,17 +3124,20 @@ nsDOMDeviceStorage::AddNamed(nsIDOMBlob*
   } else if (!typeChecker->Check(mStorageType, dsf->mFile) ||
       !typeChecker->Check(mStorageType, aBlob)) {
     r = new PostErrorEvent(request, POST_ERROR_EVENT_ILLEGAL_TYPE);
   } else {
     r = new DeviceStorageRequest(DEVICE_STORAGE_REQUEST_CREATE,
                                  win, mPrincipal, dsf, request, aBlob);
   }
 
-  NS_DispatchToMainThread(r);
+  rv = NS_DispatchToCurrentThread(r);
+  if (NS_FAILED(rv)) {
+    aRv.Throw(rv);
+  }
   return request.forget();
 }
 
 NS_IMETHODIMP
 nsDOMDeviceStorage::Get(const nsAString& aPath, nsIDOMDOMRequest** aRetval)
 {
   ErrorResult rv;
   nsRefPtr<DOMRequest> request = Get(aPath, rv);
@@ -2983,243 +3154,322 @@ nsDOMDeviceStorage::GetEditable(const ns
   request.forget(aRetval);
   return rv.ErrorCode();
 }
 
 already_AddRefed<DOMRequest>
 nsDOMDeviceStorage::GetInternal(const nsAString& aPath, bool aEditable,
                                 ErrorResult& aRv)
 {
+  MOZ_ASSERT(NS_IsMainThread());
+
   nsCOMPtr<nsPIDOMWindow> win = GetOwner();
   if (!win) {
     aRv.Throw(NS_ERROR_UNEXPECTED);
     return nullptr;
   }
 
   nsRefPtr<DOMRequest> request = new DOMRequest(win);
 
   if (IsFullPath(aPath)) {
     nsString storagePath;
     nsRefPtr<nsDOMDeviceStorage> ds = GetStorage(aPath, storagePath);
     if (!ds) {
       nsCOMPtr<nsIRunnable> r =
         new PostErrorEvent(request, POST_ERROR_EVENT_UNKNOWN);
-      NS_DispatchToMainThread(r);
+      nsresult rv = NS_DispatchToCurrentThread(r);
+      if (NS_FAILED(rv)) {
+        aRv.Throw(rv);
+      }
       return request.forget();
     }
     ds->GetInternal(win, storagePath, request, aEditable);
     return request.forget();
   }
   GetInternal(win, aPath, request, aEditable);
   return request.forget();
 }
 
 void
 nsDOMDeviceStorage::GetInternal(nsPIDOMWindow *aWin,
                                 const nsAString& aPath,
                                 DOMRequest* aRequest,
                                 bool aEditable)
 {
+  MOZ_ASSERT(NS_IsMainThread());
+
   nsRefPtr<DeviceStorageFile> dsf = new DeviceStorageFile(mStorageType,
                                                           mStorageName,
                                                           aPath);
   dsf->SetEditable(aEditable);
 
   nsCOMPtr<nsIRunnable> r;
   if (!dsf->IsSafePath()) {
     r = new PostErrorEvent(aRequest, POST_ERROR_EVENT_PERMISSION_DENIED);
   } else {
     r = new DeviceStorageRequest(aEditable ? DEVICE_STORAGE_REQUEST_WRITE
                                            : DEVICE_STORAGE_REQUEST_READ,
                                  aWin, mPrincipal, dsf, aRequest);
   }
-  NS_DispatchToMainThread(r);
+  DebugOnly<nsresult> rv = NS_DispatchToCurrentThread(r);
+  MOZ_ASSERT(NS_SUCCEEDED(rv));
 }
 
 NS_IMETHODIMP
 nsDOMDeviceStorage::Delete(const nsAString& aPath, nsIDOMDOMRequest** aRetval)
 {
   ErrorResult rv;
   nsRefPtr<DOMRequest> request = Delete(aPath, rv);
   request.forget(aRetval);
   return rv.ErrorCode();
 }
 
 already_AddRefed<DOMRequest>
 nsDOMDeviceStorage::Delete(const nsAString& aPath, ErrorResult& aRv)
 {
+  MOZ_ASSERT(NS_IsMainThread());
+
   nsCOMPtr<nsPIDOMWindow> win = GetOwner();
   if (!win) {
     aRv.Throw(NS_ERROR_UNEXPECTED);
     return nullptr;
   }
 
   nsRefPtr<DOMRequest> request = new DOMRequest(win);
 
   if (IsFullPath(aPath)) {
     nsString storagePath;
     nsRefPtr<nsDOMDeviceStorage> ds = GetStorage(aPath, storagePath);
     if (!ds) {
       nsCOMPtr<nsIRunnable> r =
         new PostErrorEvent(request, POST_ERROR_EVENT_UNKNOWN);
-      NS_DispatchToMainThread(r);
+      nsresult rv = NS_DispatchToCurrentThread(r);
+      if (NS_FAILED(rv)) {
+        aRv.Throw(rv);
+      }
       return request.forget();
     }
     ds->DeleteInternal(win, storagePath, request);
     return request.forget();
   }
   DeleteInternal(win, aPath, request);
   return request.forget();
 }
 
 void
 nsDOMDeviceStorage::DeleteInternal(nsPIDOMWindow *aWin,
                                    const nsAString& aPath,
                                    DOMRequest* aRequest)
 {
+  MOZ_ASSERT(NS_IsMainThread());
+
   nsCOMPtr<nsIRunnable> r;
   nsRefPtr<DeviceStorageFile> dsf = new DeviceStorageFile(mStorageType,
                                                           mStorageName,
                                                           aPath);
   if (!dsf->IsSafePath()) {
     r = new PostErrorEvent(aRequest, POST_ERROR_EVENT_PERMISSION_DENIED);
   } else {
     r = new DeviceStorageRequest(DEVICE_STORAGE_REQUEST_DELETE,
                                  aWin, mPrincipal, dsf, aRequest);
   }
-  NS_DispatchToMainThread(r);
+  DebugOnly<nsresult> rv = NS_DispatchToCurrentThread(r);
+  MOZ_ASSERT(NS_SUCCEEDED(rv));
 }
 
 NS_IMETHODIMP
 nsDOMDeviceStorage::FreeSpace(nsIDOMDOMRequest** aRetval)
 {
   ErrorResult rv;
   nsRefPtr<DOMRequest> request = FreeSpace(rv);
   request.forget(aRetval);
   return rv.ErrorCode();
 }
 
 already_AddRefed<DOMRequest>
 nsDOMDeviceStorage::FreeSpace(ErrorResult& aRv)
 {
+  MOZ_ASSERT(NS_IsMainThread());
+
   nsCOMPtr<nsPIDOMWindow> win = GetOwner();
   if (!win) {
     aRv.Throw(NS_ERROR_UNEXPECTED);
     return nullptr;
   }
 
   nsRefPtr<DOMRequest> request = new DOMRequest(win);
 
   nsRefPtr<DeviceStorageFile> dsf = new DeviceStorageFile(mStorageType,
                                                           mStorageName);
   nsCOMPtr<nsIRunnable> r
     = new DeviceStorageRequest(DEVICE_STORAGE_REQUEST_FREE_SPACE,
                                win, mPrincipal, dsf, request);
-  NS_DispatchToMainThread(r);
+  nsresult rv = NS_DispatchToCurrentThread(r);
+  if (NS_FAILED(rv)) {
+    aRv.Throw(rv);
+  }
   return request.forget();
 }
 
 NS_IMETHODIMP
 nsDOMDeviceStorage::UsedSpace(nsIDOMDOMRequest** aRetval)
 {
   ErrorResult rv;
   nsRefPtr<DOMRequest> request = UsedSpace(rv);
   request.forget(aRetval);
   return rv.ErrorCode();
 }
 
 already_AddRefed<DOMRequest>
 nsDOMDeviceStorage::UsedSpace(ErrorResult& aRv)
 {
+  MOZ_ASSERT(NS_IsMainThread());
+
   nsCOMPtr<nsPIDOMWindow> win = GetOwner();
   if (!win) {
     aRv.Throw(NS_ERROR_UNEXPECTED);
     return nullptr;
   }
 
   DebugOnly<DeviceStorageUsedSpaceCache*> usedSpaceCache
     = DeviceStorageUsedSpaceCache::CreateOrGet();
-  NS_ASSERTION(usedSpaceCache, "DeviceStorageUsedSpaceCache is null");
+  MOZ_ASSERT(usedSpaceCache);
 
   nsRefPtr<DOMRequest> request = new DOMRequest(win);
 
   nsRefPtr<DeviceStorageFile> dsf = new DeviceStorageFile(mStorageType,
                                                           mStorageName);
   nsCOMPtr<nsIRunnable> r
     = new DeviceStorageRequest(DEVICE_STORAGE_REQUEST_USED_SPACE,
                                win, mPrincipal, dsf, request);
-  NS_DispatchToMainThread(r);
+  nsresult rv = NS_DispatchToCurrentThread(r);
+  if (NS_FAILED(rv)) {
+    aRv.Throw(rv);
+  }
   return request.forget();
 }
 
 NS_IMETHODIMP
 nsDOMDeviceStorage::Available(nsIDOMDOMRequest** aRetval)
 {
   ErrorResult rv;
   nsRefPtr<DOMRequest> request = Available(rv);
   request.forget(aRetval);
   return rv.ErrorCode();
 }
 
 already_AddRefed<DOMRequest>
 nsDOMDeviceStorage::Available(ErrorResult& aRv)
 {
+  MOZ_ASSERT(NS_IsMainThread());
+
   nsCOMPtr<nsPIDOMWindow> win = GetOwner();
   if (!win) {
     aRv.Throw(NS_ERROR_UNEXPECTED);
     return nullptr;
   }
 
   nsRefPtr<DOMRequest> request = new DOMRequest(win);
 
   nsRefPtr<DeviceStorageFile> dsf = new DeviceStorageFile(mStorageType,
                                                           mStorageName);
   nsCOMPtr<nsIRunnable> r
     = new DeviceStorageRequest(DEVICE_STORAGE_REQUEST_AVAILABLE,
                                win, mPrincipal, dsf, request);
-  NS_DispatchToMainThread(r);
+  nsresult rv = NS_DispatchToCurrentThread(r);
+  if (NS_FAILED(rv)) {
+    aRv.Throw(rv);
+  }
   return request.forget();
 }
 
 already_AddRefed<DOMRequest>
 nsDOMDeviceStorage::Format(ErrorResult& aRv)
 {
+  MOZ_ASSERT(NS_IsMainThread());
+
   nsCOMPtr<nsPIDOMWindow> win = GetOwner();
   if (!win) {
     aRv.Throw(NS_ERROR_UNEXPECTED);
     return nullptr;
   }
 
   nsRefPtr<DOMRequest> request = new DOMRequest(win);
 
   nsRefPtr<DeviceStorageFile> dsf = new DeviceStorageFile(mStorageType,
                                                           mStorageName);
   nsCOMPtr<nsIRunnable> r
     = new DeviceStorageRequest(DEVICE_STORAGE_REQUEST_FORMAT,
                                win, mPrincipal, dsf, request);
-  NS_DispatchToMainThread(r);
+  nsresult rv = NS_DispatchToCurrentThread(r);
+  if (NS_FAILED(rv)) {
+    aRv.Throw(rv);
+  }
   return request.forget();
 }
 
 NS_IMETHODIMP
-nsDOMDeviceStorage::GetRootDirectoryForFile(const nsAString& aName,
-                                            nsIFile** aRootDirectory)
+nsDOMDeviceStorage::CreateFileDescriptor(const nsAString& aPath,
+                                         DeviceStorageFileDescriptor* aDSFileDescriptor,
+                                         nsIDOMDOMRequest** aRequest)
 {
-  nsRefPtr<nsDOMDeviceStorage> ds;
-
-  if (IsFullPath(aName)) {
-    nsString storagePath;
-    ds = GetStorage(aName, storagePath);
-  } else {
-    ds = this;
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(aDSFileDescriptor);
+
+  nsCOMPtr<nsPIDOMWindow> win = GetOwner();
+  if (!win) {
+    return NS_ERROR_UNEXPECTED;
   }
-  if (!ds || !ds->mRootDirectory) {
+
+  DeviceStorageTypeChecker* typeChecker
+    = DeviceStorageTypeChecker::CreateOrGet();
+  if (!typeChecker) {
     return NS_ERROR_FAILURE;
   }
-  return ds->mRootDirectory->Clone(aRootDirectory);
+
+  nsCOMPtr<nsIRunnable> r;
+  nsresult rv;
+
+  if (IsFullPath(aPath)) {
+    nsString storagePath;
+    nsRefPtr<nsDOMDeviceStorage> ds = GetStorage(aPath, storagePath);
+    if (!ds) {
+      nsRefPtr<DOMRequest> request = new DOMRequest(win);
+      r = new PostErrorEvent(request, POST_ERROR_EVENT_UNKNOWN);
+      rv = NS_DispatchToCurrentThread(r);
+      if (NS_FAILED(rv)) {
+        return rv;
+      }
+      request.forget(aRequest);
+      return NS_OK;
+    }
+    return ds->CreateFileDescriptor(storagePath, aDSFileDescriptor, aRequest);
+  }
+
+  nsRefPtr<DOMRequest> request = new DOMRequest(win);
+
+  nsRefPtr<DeviceStorageFile> dsf = new DeviceStorageFile(mStorageType,
+                                                          mStorageName,
+                                                          aPath);
+  if (!dsf->IsSafePath()) {
+    r = new PostErrorEvent(request, POST_ERROR_EVENT_PERMISSION_DENIED);
+  } else if (!typeChecker->Check(mStorageType, dsf->mFile)) {
+    r = new PostErrorEvent(request, POST_ERROR_EVENT_ILLEGAL_TYPE);
+  } else {
+    r = new DeviceStorageRequest(DEVICE_STORAGE_REQUEST_CREATEFD,
+                                 win, mPrincipal, dsf, request,
+                                 aDSFileDescriptor);
+  }
+
+  rv = NS_DispatchToCurrentThread(r);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  request.forget(aRequest);
+  return NS_OK;
 }
 
 bool
 nsDOMDeviceStorage::Default()
 {
   nsString defaultStorageName;
   GetDefaultStorageName(mStorageType, defaultStorageName);
   return mStorageName.Equals(defaultStorageName);
@@ -3389,17 +3639,17 @@ nsDOMDeviceStorage::Observe(nsISupports 
     if (!vol) {
       return NS_OK;
     }
     nsString volName;
     vol->GetName(volName);
 
     DeviceStorageUsedSpaceCache* usedSpaceCache
       = DeviceStorageUsedSpaceCache::CreateOrGet();
-    NS_ASSERTION(usedSpaceCache, "DeviceStorageUsedSpaceCache is null");
+    MOZ_ASSERT(usedSpaceCache);
     usedSpaceCache->Invalidate(volName);
 
     if (!volName.Equals(mStorageName)) {
       // Not our volume - we can ignore.
       return NS_OK;
     }
 
     DeviceStorageFile dsf(mStorageType, mStorageName);
@@ -3448,52 +3698,63 @@ nsDOMDeviceStorage::Notify(const char* a
 
 NS_IMETHODIMP
 nsDOMDeviceStorage::AddEventListener(const nsAString & aType,
                                      nsIDOMEventListener *aListener,
                                      bool aUseCapture,
                                      bool aWantsUntrusted,
                                      uint8_t aArgc)
 {
+  MOZ_ASSERT(NS_IsMainThread());
+
   nsCOMPtr<nsPIDOMWindow> win = GetOwner();
   if (!win) {
     return NS_ERROR_UNEXPECTED;
   }
 
   nsRefPtr<DOMRequest> request = new DOMRequest(win);
   nsRefPtr<DeviceStorageFile> dsf = new DeviceStorageFile(mStorageType,
                                                           mStorageName);
   nsCOMPtr<nsIRunnable> r
     = new DeviceStorageRequest(DEVICE_STORAGE_REQUEST_WATCH,
                                win, mPrincipal, dsf, request, this);
-  NS_DispatchToMainThread(r);
+  nsresult rv = NS_DispatchToCurrentThread(r);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
   return nsDOMEventTargetHelper::AddEventListener(aType, aListener, aUseCapture,
                                                   aWantsUntrusted, aArgc);
 }
 
 void
 nsDOMDeviceStorage::AddEventListener(const nsAString & aType,
                                      EventListener *aListener,
                                      bool aUseCapture,
                                      const Nullable<bool>& aWantsUntrusted,
                                      ErrorResult& aRv)
 {
+  MOZ_ASSERT(NS_IsMainThread());
+
   nsCOMPtr<nsPIDOMWindow> win = GetOwner();
   if (!win) {
     aRv.Throw(NS_ERROR_UNEXPECTED);
     return;
   }
 
   nsRefPtr<DOMRequest> request = new DOMRequest(win);
   nsRefPtr<DeviceStorageFile> dsf = new DeviceStorageFile(mStorageType,
                                                           mStorageName);
   nsCOMPtr<nsIRunnable> r
     = new DeviceStorageRequest(DEVICE_STORAGE_REQUEST_WATCH,
                                win, mPrincipal, dsf, request, this);
-  NS_DispatchToMainThread(r);
+  nsresult rv = NS_DispatchToCurrentThread(r);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return;
+  }
   nsDOMEventTargetHelper::AddEventListener(aType, aListener, aUseCapture,
                                            aWantsUntrusted, aRv);
 }
 
 NS_IMETHODIMP
 nsDOMDeviceStorage::AddSystemEventListener(const nsAString & aType,
                                            nsIDOMEventListener *aListener,
                                            bool aUseCapture,