--- a/browser/base/content/browser.xul
+++ b/browser/base/content/browser.xul
@@ -1181,25 +1181,24 @@
                          tooltiptext="&devToolbarCloseButton.tooltiptext;"/>
 #endif
    </toolbar>
   </vbox>
 
   <svg:svg height="0">
 #include tab-shape.inc.svg
 
-#ifndef XP_UNIX
-    <svg:clipPath id="windows-keyhole-forward-clip-path" clipPathUnits="userSpaceOnUse">
+#ifndef XP_MACOSX
+    <svg:clipPath id="keyhole-forward-clip-path" clipPathUnits="userSpaceOnUse">
       <svg:path d="M 0,0 a 16 16 0 0 1 0,24 l 10000,0 l 0,-24 l -10000,0 z"/>
     </svg:clipPath>
-    <svg:clipPath id="windows-urlbar-back-button-clip-path" clipPathUnits="userSpaceOnUse">
+    <svg:clipPath id="urlbar-back-button-clip-path" clipPathUnits="userSpaceOnUse">
       <svg:path d="M -1,1 a 16 16 0 0 1 0,24 l 10000,0 l 0,-24 l -10000,0 z"/>
     </svg:clipPath>
-#endif
-#ifdef XP_MACOSX
+#else
     <svg:clipPath id="osx-keyhole-forward-clip-path" clipPathUnits="userSpaceOnUse">
       <svg:path d="M 0,0 a 16 16 0 0 1 0,24 l 10000,0 l 0,-24 l -10000,0 z"/>
     </svg:clipPath>
     <svg:clipPath id="osx-urlbar-back-button-clip-path" clipPathUnits="userSpaceOnUse">
       <svg:path d="M -12,-5 a 16 16 0 0 1 0,34 l 10000,0 l 0,-34 l -10000,0 z"/>
     </svg:clipPath>
 #endif
   </svg:svg>

--- a/browser/themes/linux/browser.css
+++ b/browser/themes/linux/browser.css
@@ -10,17 +10,17 @@
 @namespace html url("http://www.w3.org/1999/xhtml");
 
 %include ../shared/browser.inc
 %include linuxShared.inc
 %filter substitution
 
 %define forwardTransitionLength 150ms
 %define conditionalForwardWithUrlbar window:not([chromehidden~="toolbar"]) #urlbar-container
-%define conditionalForwardWithUrlbarWidth 40
+%define conditionalForwardWithUrlbarWidth 30
 
 #menubar-items {
   -moz-box-orient: vertical; /* for flex hack */
 }
 
 #main-menubar {
   -moz-box-flex: 1; /* make menu items expand to fill toolbar height */
 }
@@ -663,31 +663,106 @@ toolbarbutton[sdk-button="true"][cui-are
   background-position: center;
   background-repeat: no-repeat;
   background-size: 1px 18px;
   box-shadow: 0 0 0 1px hsla(0,0%,100%,.2);
 }
 
 :-moz-any(#TabsToolbar, #nav-bar) .toolbarbutton-1 > .toolbarbutton-menubutton-dropmarker {
   -moz-margin-start: -4px;
+  margin-top: 3px;
+  margin-bottom: 3px;
+}
+
+#back-button {
+  padding-top: 3px;
+  padding-bottom: 3px;
+  -moz-padding-start: 5px;
+  -moz-padding-end: 0;
+  position: relative;
+  z-index: 1;
+  border-radius: 0 10000px 10000px 0;
+}
+
+#back-button:-moz-locale-dir(rtl) {
+  border-radius: 10000px 0 0 10000px;
+}
+
+#back-button > menupopup {
+  margin-top: -1px;
 }
 
-#forward-button[disabled] {
-  transform: scale(0);
+#back-button > .toolbarbutton-icon {
+  border-radius: 10000px;
+  background-clip: padding-box;
+  padding: 6px;
+  border: none;
+  box-shadow: 0 1px 0 hsla(0,0%,100%,.3) inset,
+              0 0 0 1px hsla(0,0%,100%,.3) inset,
+              0 0 0 1px hsla(210,54%,20%,.25),
+              0 1px 0 hsla(210,54%,20%,.35);
+  background-image: linear-gradient(hsla(0,0%,100%,.6), hsla(0,0%,100%,.1));
+  transition-property: background-color, box-shadow;
+  transition-duration: 250ms;
+}
+
+#back-button:not([disabled="true"]):not([open="true"]):not(:active):hover > .toolbarbutton-icon {
+  background-color: hsla(210,48%,96%,.75);
+  box-shadow: 0 1px 0 hsla(0,0%,100%,.3) inset,
+              0 0 0 1px hsla(0,0%,100%,.3) inset,
+              0 0 0 1px hsla(210,54%,20%,.3),
+              0 1px 0 hsla(210,54%,20%,.4),
+              0 0 4px hsla(210,54%,20%,.2);
+}
+
+#back-button:not([disabled="true"]):hover:active > .toolbarbutton-icon,
+#back-button[open="true"] > .toolbarbutton-icon {
+  background-color: hsla(210,54%,20%,.15);
+  box-shadow: 0 1px 1px hsla(210,54%,20%,.1) inset,
+              0 0 1px hsla(210,54%,20%,.2) inset,
+              0 0 0 1px hsla(210,54%,20%,.4),
+              0 1px 0 hsla(210,54%,20%,.2);
+  transition: none;
+}
+
+#main-window:not([customizing]) #back-button[disabled] > .toolbarbutton-icon {
+  box-shadow: 0 0 0 1px hsla(210,54%,20%,.55),
+              0 1px 0 hsla(210,54%,20%,.65) !important;
+  transition: none;
+}
+
+#back-button:-moz-locale-dir(rtl) > .toolbarbutton-icon,
+#forward-button:-moz-locale-dir(rtl) {
+  transform: scaleX(-1);
+}
+
+@conditionalForwardWithUrlbar@:not(:hover) > #forward-button[disabled] {
   opacity: 0;
-  pointer-events: none;
 }
 
 @conditionalForwardWithUrlbar@:not([switchingtabs]) > #forward-button {
-  transition: @forwardTransitionLength@ ease-out;
+  transition: opacity @forwardTransitionLength@ ease-out;
+}
+
+@conditionalForwardWithUrlbar@ > #forward-button[occluded-by-urlbar] {
+  visibility: hidden;
 }
 
-#back-button:-moz-locale-dir(rtl) > .toolbarbutton-icon,
-#forward-button:-moz-locale-dir(rtl) > .toolbarbutton-icon {
-  transform: scaleX(-1);
+#forward-button {
+  padding: 0;
+}
+
+#forward-button > .toolbarbutton-icon {
+  background-clip: padding-box;
+  clip-path: url("chrome://browser/content/browser.xul#keyhole-forward-clip-path");
+  margin-left: -6px;
+  border-left-style: none;
+  border-radius: 0;
+  padding: 2px 3px 2px 9px;
+  border: 1px solid #9a9a9a;
 }
 
 /* tabview menu item */
 
 #menu_tabview {
   list-style-image: url(chrome://browser/skin/tabview/tabview.png);
   -moz-image-region: rect(0, 80px, 16px, 64px);
 }
@@ -782,19 +857,31 @@ toolbarbutton[sdk-button="true"][cui-are
 #restore-button {
   list-style-image: url("chrome://global/skin/icons/Restore.gif");
 }
 #close-button {
   list-style-image: url("chrome://global/skin/icons/Close.gif");
 }
 
 /* Location bar */
+#urlbar,
+.searchbar-textbox {
+  -moz-appearance: none;
+  padding: 1px;
+  border: 1px solid ThreeDShadow;
+  border-radius: 2px;
+}
+
+#urlbar[focused],
+.searchbar-textbox[focused] {
+  border-color: Highlight;
+}
+
 #urlbar {
-  -moz-appearance: textfield;
-  padding: 0;
+  background-color: -moz-field;
 }
 
 .urlbar-textbox-container {
   -moz-appearance: none;
   -moz-box-align: stretch;
 }
 
 .urlbar-input-box {
@@ -806,36 +893,69 @@ toolbarbutton[sdk-button="true"][cui-are
 }
 
 #urlbar-container {
   -moz-box-orient: horizontal;
   -moz-box-align: stretch;
 }
 
 @conditionalForwardWithUrlbar@ > #urlbar-wrapper {
-  -moz-padding-start: @conditionalForwardWithUrlbarWidth@px;
+  padding-left: @conditionalForwardWithUrlbarWidth@px;
   -moz-margin-start: -@conditionalForwardWithUrlbarWidth@px;
   position: relative;
   pointer-events: none;
 }
 
 @conditionalForwardWithUrlbar@ > #urlbar-wrapper > #urlbar {
+  -moz-border-start: none;
+  margin-left: 0;
   pointer-events: all;
 }
 
 @conditionalForwardWithUrlbar@:not([switchingtabs]) > #urlbar-wrapper > #urlbar {
-  transition: margin-left @forwardTransitionLength@ ease-out,
-              margin-right @forwardTransitionLength@ ease-out;
+  transition: margin-left @forwardTransitionLength@ ease-out;
+}
+
+@conditionalForwardWithUrlbar@ > #urlbar-wrapper > #urlbar:-moz-locale-dir(ltr) {
+  border-top-left-radius: 0;
+  border-bottom-left-radius: 0;
+}
+
+@conditionalForwardWithUrlbar@ > #urlbar-wrapper > #urlbar:-moz-locale-dir(rtl) {
+  border-top-right-radius: 0;
+  border-bottom-right-radius: 0;
+}
+
+@conditionalForwardWithUrlbar@[forwarddisabled] > #urlbar-wrapper {
+  /* Work with margin-top to align the clip-path correctly. */
+  margin-top: 5px;
+  clip-path: url("chrome://browser/content/browser.xul#urlbar-back-button-clip-path");
 }
 
-@conditionalForwardWithUrlbar@[forwarddisabled] > #urlbar-wrapper > #urlbar:-moz-locale-dir(ltr) {
+@conditionalForwardWithUrlbar@[forwarddisabled] > #urlbar-wrapper > #urlbar {
+  margin-top: -4px;
   margin-left: -@conditionalForwardWithUrlbarWidth@px;
 }
-@conditionalForwardWithUrlbar@[forwarddisabled] > #urlbar-wrapper > #urlbar:-moz-locale-dir(rtl) {
-  margin-right: -@conditionalForwardWithUrlbarWidth@px;
+
+@conditionalForwardWithUrlbar@[forwarddisabled]:hover:not([switchingtabs]) > #urlbar-wrapper > #urlbar {
+  /* delay the hiding of the forward button when hovered to avoid accidental clicks on the url bar */
+  transition-delay: 100s;
+}
+
+@conditionalForwardWithUrlbar@[forwarddisabled][switchingtabs] + #urlbar-container > #urlbar,
+@conditionalForwardWithUrlbar@[forwarddisabled]:not(:hover) > #urlbar-wrapper > #urlbar {
+  /* when switching tabs, or when not hovered anymore, trigger a new transition
+   * to hide the forward button immediately */
+  margin-left: -@conditionalForwardWithUrlbarWidth@.01px;
+}
+
+@conditionalForwardWithUrlbar@ > #urlbar-wrapper:-moz-locale-dir(rtl),
+@conditionalForwardWithUrlbar@ > #urlbar-wrapper > #urlbar:-moz-locale-dir(rtl) {
+  /* let windows-urlbar-back-button-mask clip the urlbar's right side for RTL */
+  transform: scaleX(-1);
 }
 
 #urlbar-icons {
   -moz-box-align: center;
 }
 
 .urlbar-icon {
   cursor: pointer;
@@ -865,67 +985,109 @@ toolbarbutton[sdk-button="true"][cui-are
   -moz-margin-start: 0;
   color: GrayText;
 }
 
 #search-container {
   min-width: calc(54px + 11ch);
 }
 
-%include ../shared/identity-block.inc.css
-
-#page-proxy-favicon {
-  margin-top: 2px;
-  margin-bottom: 2px;
-  -moz-margin-start: 4px;
-  -moz-margin-end: 3px;
-  -moz-image-region: rect(0, 16px, 16px, 0);
-}
+/* identity box */
 
-#identity-box:hover > #page-proxy-favicon {
-  -moz-image-region: rect(0, 32px, 16px, 16px);
-}
-
-#identity-box:hover:active > #page-proxy-favicon,
-#identity-box[open=true] > #page-proxy-favicon {
-  -moz-image-region: rect(0, 48px, 16px, 32px);
-}
-
-/* Identity indicator */
 #identity-box {
   padding: 1px;
-  margin: -1px;
-  -moz-margin-end: 0;
   font-size: .9em;
 }
 
 #identity-box:-moz-locale-dir(ltr) {
-  border-top-left-radius: 2.5px;
-  border-bottom-left-radius: 2.5px;
+  border-top-left-radius: 1.5px;
+  border-bottom-left-radius: 1.5px;
 }
 
 #identity-box:-moz-locale-dir(rtl) {
-  border-top-right-radius: 2.5px;
-  border-bottom-right-radius: 2.5px;
+  border-top-right-radius: 1.5px;
+  border-bottom-right-radius: 1.5px;
+}
+
+#notification-popup-box:not([hidden]) + #identity-box {
+  -moz-padding-start: 10px;
+  border-radius: 0;
+}
+
+@conditionalForwardWithUrlbar@ > #urlbar-wrapper > #urlbar > #identity-box {
+  border-radius: 0;
+}
+
+@conditionalForwardWithUrlbar@[forwarddisabled] > #urlbar-wrapper > #urlbar > #notification-popup-box[hidden] + #identity-box:-moz-locale-dir(ltr) {
+  padding-left: 5px;
+  transition: padding-left;
+}
+
+@conditionalForwardWithUrlbar@[forwarddisabled] > #urlbar-wrapper > #urlbar > #notification-popup-box[hidden] + #identity-box:-moz-locale-dir(rtl) {
+  padding-right: 5px;
+  transition: padding-right;
+}
+
+@conditionalForwardWithUrlbar@[forwarddisabled]:hover:not([switchingtabs]) > #urlbar-wrapper > #urlbar > #notification-popup-box[hidden] + #identity-box {
+  /* forward button hiding is delayed when hovered */
+  transition-delay: 100s;
+}
+
+@conditionalForwardWithUrlbar@[forwarddisabled][switchingtabs] + #urlbar-container > #urlbar > #notification-popup-box[hidden] + #identity-box:-moz-locale-dir(ltr),
+@conditionalForwardWithUrlbar@[forwarddisabled]:not(:hover) > #urlbar-wrapper > #urlbar > #notification-popup-box[hidden] + #identity-box:-moz-locale-dir(ltr) {
+  /* when not hovered anymore, trigger a new non-delayed transition to react to the forward button hiding */
+  padding-left: 5.01px;
+}
+
+@conditionalForwardWithUrlbar@[forwarddisabled][switchingtabs] + #urlbar-container > #urlbar > #notification-popup-box[hidden] + #identity-box:-moz-locale-dir(rtl),
+@conditionalForwardWithUrlbar@[forwarddisabled]:not(:hover) > #urlbar-wrapper > #urlbar > #notification-popup-box[hidden] + #identity-box:-moz-locale-dir(rtl) {
+  /* when not hovered anymore, trigger a new non-delayed transition to react to the forward button hiding */
+  padding-right: 5.01px;
+}
+
+#urlbar[pageproxystate="valid"] > #identity-box.chromeUI,
+#urlbar[pageproxystate="valid"] > #identity-box.verifiedIdentity {
+  -moz-margin-end: 4px;
+}
+
+#identity-box.verifiedIdentity:not(:-moz-lwtheme) {
+  background-color: #fff;
 }
 
 #identity-box:-moz-focusring {
   outline: 1px dotted #000;
   outline-offset: -3px;
 }
 
 #identity-icon-labels {
   -moz-padding-start: 2px;
   -moz-padding-end: 5px;
 }
 
-#urlbar[pageproxystate="valid"] > #identity-box.chromeUI,
-#urlbar[pageproxystate="valid"] > #identity-box.verifiedIdentity {
-  background-color: #fff;
-  -moz-margin-end: 4px;
+%include ../shared/identity-block.inc.css
+
+#page-proxy-favicon {
+  margin-top: 1px;
+  margin-bottom: 1px;
+  -moz-margin-start: 3px;
+  -moz-margin-end: 2px;
+  -moz-image-region: rect(0, 16px, 16px, 0);
+}
+
+@conditionalForwardWithUrlbar@ > #urlbar-wrapper > #urlbar > #identity-box > #page-proxy-favicon {
+  -moz-margin-end: 1px;
+}
+
+#identity-box:hover > #page-proxy-favicon {
+  -moz-image-region: rect(0, 32px, 16px, 16px);
+}
+
+#identity-box:hover:active > #page-proxy-favicon,
+#identity-box[open=true] > #page-proxy-favicon {
+  -moz-image-region: rect(0, 48px, 16px, 32px);
 }
 
 /* Identity popup icons */
 #identity-popup-icon {
   height: 64px;
   width: 64px;
   padding: 0;
   list-style-image: url("chrome://browser/skin/identity.png");

--- a/browser/themes/windows/browser.css
+++ b/browser/themes/windows/browser.css
@@ -807,17 +807,17 @@ toolbarbutton[sdk-button="true"][cui-are
   #nav-bar .toolbarbutton-1:not([disabled]):-moz-any([open],[checked],:hover:active) > .toolbarbutton-icon,
   #nav-bar .toolbarbutton-1:not([disabled]):-moz-any([open],[checked],:hover:active) > .toolbarbutton-text,
   #nav-bar .toolbarbutton-1:not([disabled]):-moz-any([open],[checked],:hover:active) > .toolbarbutton-badge-container {
     background-image: linear-gradient(hsla(0,0%,100%,.6), hsla(0,0%,100%,.1));
     background-color: hsla(210,54%,20%,.15);
     border-color: hsla(210,54%,20%,.3) hsla(210,54%,20%,.35) hsla(210,54%,20%,.4);
     box-shadow: 0 1px 1px hsla(210,54%,20%,.1) inset,
                 0 0 1px hsla(210,54%,20%,.2) inset,
-                /* allows windows-keyhole-forward-clip-path to be used for non-hover as well as hover: */
+                /* allows keyhole-forward-clip-path to be used for non-hover as well as hover: */
                 0 1px 0 hsla(210,54%,20%,0),
                 0 0 2px hsla(210,54%,20%,0);
     text-shadow: none;
     transition: none;
   }
 
   #nav-bar .toolbarbutton-1:-moz-any(:hover,[open]) > .toolbarbutton-menubutton-dropmarker:not([disabled]) > .dropmarker-icon {
     -moz-border-start-color: hsla(210,54%,20%,.35);
@@ -865,17 +865,17 @@ toolbarbutton[sdk-button="true"][cui-are
 
 #forward-button > menupopup {
   margin-top: 1px !important;
 }
 
 #forward-button > .toolbarbutton-icon {
   background-clip: padding-box !important;
   /*mask: url(keyhole-forward-mask.svg#mask); XXX: this regresses twinopen */
-  clip-path: url(chrome://browser/content/browser.xul#windows-keyhole-forward-clip-path) !important;
+  clip-path: url(chrome://browser/content/browser.xul#keyhole-forward-clip-path) !important;
   margin-left: -6px !important;
   border-left-style: none !important;
   border-radius: 0 !important;
   padding-left: 9px !important;
   padding-right: 3px !important;
 }
 
 %ifdef WINDOWS_AERO
@@ -1168,17 +1168,17 @@ toolbarbutton[sdk-button="true"][cui-are
 }
 
 @conditionalForwardWithUrlbar@ > #urlbar-wrapper > #urlbar:-moz-locale-dir(rtl) {
   border-top-right-radius: 0;
   border-bottom-right-radius: 0;
 }
 
 @conditionalForwardWithUrlbar@[forwarddisabled] > #urlbar-wrapper {
-  clip-path: url("chrome://browser/content/browser.xul#windows-urlbar-back-button-clip-path");
+  clip-path: url("chrome://browser/content/browser.xul#urlbar-back-button-clip-path");
 }
 
 @conditionalForwardWithUrlbar@[forwarddisabled] > #urlbar-wrapper > #urlbar {
   margin-left: -@conditionalForwardWithUrlbarWidth@px;
 }
 
 @conditionalForwardWithUrlbar@[forwarddisabled]:hover:not([switchingtabs]) > #urlbar-wrapper > #urlbar {
   /* delay the hiding of the forward button when hovered to avoid accidental clicks on the url bar */