Backed out changeset d670f361bbb6

browser/base/content/browser.js

@@ -4428,8 +4428,7 @@ var TabsInTitlebar = {
 
       // Get the full height of the tabs toolbar:
       let tabsToolbar = $("TabsToolbar");
-      let tabsStyles = window.getComputedStyle(tabsToolbar);
-      let fullTabsHeight = rect(tabsToolbar).height + verticalMargins(tabsStyles);
+      let fullTabsHeight = rect(tabsToolbar).height;
       // Buttons first:
       let captionButtonsBoxWidth = rect($("titlebar-buttonbox-container")).width;
 
@@ -4438,11 +4437,15 @@ var TabsInTitlebar = {
       // No need to look up the menubar stuff on OS X:
       let menuHeight = 0;
       let fullMenuHeight = 0;
+      // Instead, look up the titlebar padding:
+      let titlebarPadding = parseInt(window.getComputedStyle(titlebar).paddingTop, 10);
 #else
       // Otherwise, get the height and margins separately for the menubar
       let menuHeight = rect(menubar).height;
       let menuStyles = window.getComputedStyle(menubar);
       let fullMenuHeight = verticalMargins(menuStyles) + menuHeight;
+      let tabsStyles = window.getComputedStyle(tabsToolbar);
+      fullTabsHeight += verticalMargins(tabsStyles);
 #endif
 
       // And get the height of what's in the titlebar:
@@ -4485,6 +4488,7 @@ var TabsInTitlebar = {
         // We need to increase the titlebar content's outer height (ie including margins)
         // to match the tab and menu height:
         let extraMargin = tabAndMenuHeight - titlebarContentHeight;
+        // On non-OSX, we can just use bottom margin:
 #ifndef XP_MACOSX
         titlebarContent.style.marginBottom = extraMargin + "px";
 #endif

browser/components/customizableui/test/browser_938980_navbar_collapsed.js

@@ -31,7 +31,7 @@ add_task(function() {
   setToolbarVisibility(bookmarksToolbar, true);
   setToolbarVisibility(navbar, false);
   isnot(bookmarksToolbar.getBoundingClientRect().height, 0, "bookmarksToolbar should be visible now");
-  is(navbar.getBoundingClientRect().height, 0, "navbar should have height=0");
+  is(navbar.getBoundingClientRect().height, 1, "navbar should have a height=1 (due to border)");
   is(CustomizableUI.inDefaultState, false, "Should no longer be in default state");
 
   yield startCustomizing();

browser/themes/linux/browser.css

@@ -52,6 +52,7 @@
 }
 
 #TabsToolbar:not([collapsed="true"]) + #nav-bar {
+  margin-top: -@tabToolbarNavbarOverlap@; /* Move up into the TabsToolbar */
   /* Position the toolbar above the bottom of background tabs */
   position: relative;
   z-index: 1;
@@ -1767,7 +1768,6 @@ richlistitem[type~="action"][actiontype="switchtab"] > .ac-url-box > .ac-action-
   min-height: 0;
   padding: 0;
   position: relative;
-  margin-bottom: -@tabToolbarNavbarOverlap@;
 }
 
 /*

browser/themes/osx/browser.css

@@ -110,6 +110,7 @@ toolbarseparator {
 }
 
 #TabsToolbar:not([collapsed="true"]) + #nav-bar {
+  margin-top: -@tabToolbarNavbarOverlap@; /* Move up into the TabsToolbar */
   /* Position the toolbar above the bottom of background tabs */
   position: relative;
   z-index: 1;
@@ -2796,7 +2797,6 @@ toolbarbutton.chevron > .toolbarbutton-menu-dropmarker {
   position: relative;
   -moz-appearance: none;
   background-repeat: repeat-x;
-  margin-bottom: -@tabToolbarNavbarOverlap@;
 }
 
 #TabsToolbar:not(:-moz-lwtheme) {