--- a/b2g/config/gaia.json
+++ b/b2g/config/gaia.json
@@ -1,4 +1,4 @@
 {
-    "revision": "d39f167ee1b770d2312a7b35bbcb29afe83b5c4f", 
+    "revision": "5c08f3d8a2b96b15b232dae43a2428fcdca61a79", 
     "repo_path": "/integration/gaia-central"
 }

--- a/b2g/config/leo/releng-leo.tt
+++ b/b2g/config/leo/releng-leo.tt
@@ -1,12 +1,12 @@
 [
 {
-"size": 141304652,
-"digest": "0bbba7483a483803fa0277ddeeb3f8f9592b57cb83d57794c366fb8a3541b47f0ab901c071b7ceb6828bceec7170e5d5c05c5b1dcc926c70f3da46a7e224f078",
+"size": 117247732,
+"digest": "16e74278e4e9b0d710df77d68af1677c91823dccfc611ab00ee617298a63787f9f9892bd1a41eccb8d45fb18d61bfda0dbd1de88f1861c14b4b44da3b94a4eca",
 "algorithm": "sha512",
 "filename": "backup-leo.tar.xz"
 },
 {
 "size": 1570553,
 "digest": "ea03de74df73b05e939c314cd15c54aac7b5488a407b7cc4f5f263f3049a1f69642c567dd35c43d0bc3f0d599d0385a26ab2dd947a6b18f9044e4918b382eea7",
 "algorithm": "sha512",
 "filename": "Adreno200-AU_LINUX_ANDROID_ICS_CHOCO_CS.04.00.03.06.001.zip"

--- a/dom/apps/src/Webapps.jsm
+++ b/dom/apps/src/Webapps.jsm
@@ -2540,41 +2540,16 @@ this.DOMApplicationRegistry = {
                                                 aManifest._manifest)) {
                   throw "MANIFEST_MISMATCH";
                 }
 
                 if (!AppsUtils.checkInstallAllowed(manifest, aApp.installOrigin)) {
                   throw "INSTALL_FROM_DENIED";
                 }
 
-                // Get ids.json if the file is signed
-                if (isSigned) {
-                  let idsStream;
-                  try {
-                    idsStream = zipReader.getInputStream("META-INF/ids.json");
-                  } catch (e) {
-                    throw zipReader.hasEntry("META-INF/ids.json")
-                          ? e
-                          : "MISSING_IDS_JSON";
-                  }
-                  let ids =
-                    JSON.parse(
-                      converter.ConvertToUnicode(
-                        NetUtil.readInputStreamToString(
-                          idsStream, idsStream.available()) || ""));
-                  if ((!ids.id) || !Number.isInteger(ids.version) ||
-                      (ids.version <= 0)) {
-                     throw "INVALID_IDS_JSON";
-                  }
-                  let storeId = aApp.installOrigin + "#" + ids.id;
-                  checkForStoreIdMatch(storeId, ids.version);
-                  app.storeId = storeId;
-                  app.storeVersion = ids.version;
-                }
-
                 let maxStatus = isSigned ? Ci.nsIPrincipal.APP_STATUS_PRIVILEGED
                                          : Ci.nsIPrincipal.APP_STATUS_INSTALLED;
 
                 if (AppsUtils.getAppManifestStatus(manifest) > maxStatus) {
                   throw "INVALID_SECURITY_LEVEL";
                 }
                 app.appStatus = AppsUtils.getAppManifestStatus(manifest);
 
@@ -2609,48 +2584,77 @@ this.DOMApplicationRegistry = {
                   } catch(e) {
                     throw "INVALID_ORIGIN";
                   }
 
                   if (uri.scheme != "app") {
                     throw "INVALID_ORIGIN";
                   }
 
-                  // Changing the origin during an update is not allowed.
-                  if (aIsUpdate && uri.prePath != app.origin) {
-                    throw "INVALID_ORIGIN_CHANGE";
-                  }
-
-                  debug("Setting origin to " + uri.prePath +
-                        " for " + app.manifestURL);
-                  let newId = uri.prePath.substring(6); // "app://".length
-
-                  if (newId in self.webapps) {
-                    throw "DUPLICATE_ORIGIN";
+                  if (aIsUpdate) {
+                    // Changing the origin during an update is not allowed.
+                    if (uri.prePath != app.origin) {
+                      throw "INVALID_ORIGIN_CHANGE";
+                    }
+                    // Nothing else to do for an update... since the
+                    // origin can't change we don't need to move the
+                    // app nor can we have a duplicated origin
+                  } else {
+                    debug("Setting origin to " + uri.prePath +
+                          " for " + app.manifestURL);
+                    let newId = uri.prePath.substring(6); // "app://".length
+
+                    if (newId in self.webapps) {
+                      throw "DUPLICATE_ORIGIN";
+                    }
+                    app.origin = uri.prePath;
+
+                    app.id = newId;
+                    self.webapps[newId] = app;
+                    delete self.webapps[id];
+
+                    // Rename the directories where the files are installed.
+                    [DIRECTORY_NAME, "TmpD"].forEach(function(aDir) {
+                        let parent = FileUtils.getDir(aDir,
+                          ["webapps"], true, true);
+                        let dir = FileUtils.getDir(aDir,
+                          ["webapps", id], true, true);
+                        dir.moveTo(parent, newId);
+                    });
+
+                    // Signals that we need to swap the old id with the new app.
+                    self.broadcastMessage("Webapps:RemoveApp", { id: id });
+                    self.broadcastMessage("Webapps:AddApp", { id: newId,
+                                                              app: app });
                   }
-                  app.origin = uri.prePath;
-
-                  // Update the registry.
-                  app.id = newId;
-                  self.webapps[newId] = app;
-                  delete self.webapps[id];
-
-                  // Rename the directories where the files are installed.
-                  [DIRECTORY_NAME, "TmpD"].forEach(function(aDir) {
-                    let parent = FileUtils.getDir(aDir,
-                                             ["webapps"], true, true);
-                    let dir = FileUtils.getDir(aDir,
-                                             ["webapps", id], true, true);
-                    dir.moveTo(parent, newId);
-                  });
-
-                  // Signals that we need to swap the old id with the new app.
-                  self.broadcastMessage("Webapps:RemoveApp", { id: id });
-                  self.broadcastMessage("Webapps:AddApp", { id: newId,
-                                                            app: app });
+                }
+
+                // Get ids.json if the file is signed
+                if (isSigned) {
+                  let idsStream;
+                  try {
+                    idsStream = zipReader.getInputStream("META-INF/ids.json");
+                  } catch (e) {
+                    throw zipReader.hasEntry("META-INF/ids.json")
+                          ? e
+                          : "MISSING_IDS_JSON";
+                  }
+                  let ids =
+                    JSON.parse(
+                      converter.ConvertToUnicode(
+                        NetUtil.readInputStreamToString(
+                          idsStream, idsStream.available()) || ""));
+                  if ((!ids.id) || !Number.isInteger(ids.version) ||
+                      (ids.version <= 0)) {
+                     throw "INVALID_IDS_JSON";
+                  }
+                  let storeId = aApp.installOrigin + "#" + ids.id;
+                  checkForStoreIdMatch(storeId, ids.version);
+                  app.storeId = storeId;
+                  app.storeVersion = ids.version;
                 }
 
                 if (aOnSuccess) {
                   aOnSuccess(app.id, manifest);
                 }
               } catch (e) {
                 // Something bad happened when reading the package.
                 // Unrecoverable error, don't bug the user.

--- a/dom/browser-element/BrowserElementChildPreload.js
+++ b/dom/browser-element/BrowserElementChildPreload.js
@@ -259,18 +259,19 @@ BrowserElementChild.prototype = {
                              /* ownsWeak = */ true);
 
     Services.obs.addObserver(this,
                              'xpcom-shutdown',
                              /* ownsWeak = */ true);
   },
 
   observe: function(subject, topic, data) {
-    // Ignore notifications not about our document.
-    if (subject != content.document)
+    // Ignore notifications not about our document.  (Note that |content| /can/
+    // be null; see bug 874900.)
+    if (!content || subject != content.document)
       return;
     switch (topic) {
       case 'fullscreen-origin-change':
         sendAsyncMsg('fullscreen-origin-change', { _payload_: data });
         break;
       case 'ask-parent-to-exit-fullscreen':
         sendAsyncMsg('exit-fullscreen');
         break;

--- a/dom/system/gonk/AutoMounter.cpp
+++ b/dom/system/gonk/AutoMounter.cpp
@@ -13,16 +13,17 @@
 #include <arpa/inet.h>
 #include <linux/types.h>
 #include <linux/netlink.h>
 #include <netinet/in.h>
 #include <sys/socket.h>
 #include <android/log.h>
 
 #include "AutoMounter.h"
+#include "nsVolumeService.h"
 #include "AutoMounterSetting.h"
 #include "base/message_loop.h"
 #include "mozilla/FileUtils.h"
 #include "mozilla/Hal.h"
 #include "mozilla/StaticPtr.h"
 #include "nsAutoPtr.h"
 #include "nsMemory.h"
 #include "nsString.h"
@@ -562,19 +563,78 @@ public:
         FROM_HERE,
         NewRunnableFunction(UsbCableEventIOThread));
   }
 };
 
 static StaticRefPtr<UsbCableObserver> sUsbCableObserver;
 static StaticRefPtr<AutoMounterSetting> sAutoMounterSetting;
 
+static void
+InitVolumeConfig()
+{
+  // This function uses /system/etc/volume.cfg to add additional volumes
+  // to the Volume Manager.
+  //
+  // This is useful on devices like the Nexus 4, which have no physical sd card
+  // or dedicated partition.
+  //
+  // The format of the volume.cfg file is as follows:
+  // create volume-name mount-point
+  // Blank lines and lines starting with the hash character "#" will be ignored.
+
+  nsCOMPtr<nsIVolumeService> vs = do_GetService(NS_VOLUMESERVICE_CONTRACTID);
+  NS_ENSURE_TRUE_VOID(vs);
+
+  ScopedCloseFile fp;
+  int n = 0;
+  char line[255];
+  char *command, *vol_name_cstr, *mount_point_cstr, *save_ptr;
+  const char *filename = "/system/etc/volume.cfg";
+  if (!(fp = fopen(filename, "r"))) {
+    LOG("Unable to open volume configuration file '%s' - ignoring", filename);
+    return;
+  }
+  while(fgets(line, sizeof(line), fp)) {
+    char *delim = " \t\n";
+    n++;
+
+    if (line[0] == '#')
+      continue;
+    if (!(command = strtok_r(line, delim, &save_ptr))) {
+      // Blank line - ignore
+      continue;
+    }
+    if (!strcmp(command, "create")) {
+      if (!(vol_name_cstr = strtok_r(NULL, delim, &save_ptr))) {
+        ERR("No vol_name in %s line %d",  filename, n);
+        continue;
+      }
+      if (!(mount_point_cstr = strtok_r(NULL, delim, &save_ptr))) {
+        ERR("No mount point for volume '%s'. %s line %d", vol_name_cstr, filename, n);
+        continue;
+      }
+      nsString  mount_point = NS_ConvertUTF8toUTF16(mount_point_cstr);
+      nsString vol_name = NS_ConvertUTF8toUTF16(vol_name_cstr);
+      nsresult rv;
+      rv = vs->CreateFakeVolume(vol_name, mount_point);
+      NS_ENSURE_SUCCESS_VOID(rv);
+      rv = vs->SetFakeVolumeState(vol_name, nsIVolume::STATE_MOUNTED);
+      NS_ENSURE_SUCCESS_VOID(rv);
+    }
+    else {
+      ERR("Unrecognized command: '%s'", command);
+    }
+  }
+}
+
 void
 InitAutoMounter()
 {
+  InitVolumeConfig();
   InitVolumeManager();
   sAutoMounterSetting = new AutoMounterSetting();
 
   XRE_GetIOMessageLoop()->PostTask(
       FROM_HERE,
       NewRunnableFunction(InitAutoMounterIOThread));
 
   // Switch Observers need to run on the main thread, so we need to

--- a/xpcom/glue/FileUtils.h
+++ b/xpcom/glue/FileUtils.h
@@ -63,16 +63,29 @@ struct ScopedClosePRFDTraits
   static void release(type fd) {
     if (fd != NULL) {
       PR_Close(fd);
     }
   }
 };
 typedef Scoped<ScopedClosePRFDTraits> AutoFDClose;
 
+/* RAII wrapper for FILE descriptors */
+struct ScopedCloseFileTraits
+{
+  typedef FILE *type;
+  static type empty() { return nullptr; }
+  static void release(type f) {
+    if (f) {
+      fclose(f);
+    }
+  }
+};
+typedef Scoped<ScopedCloseFileTraits> ScopedCloseFile;
+
 /**
  * Fallocate efficiently and continuously allocates files via fallocate-type APIs.
  * This is useful for avoiding fragmentation.
  * On sucess the file be padded with zeros to grow to aLength.
  *
  * @param aFD file descriptor.
  * @param aLength length of file to grow to.
  * @return true on success.