From b04a754b736b2dabc75e4a95fbca22ae5304163e Mon Sep 17 00:00:00 2001
From: Tim Taubert <ttaubert@mozilla.com>
Date: Tue, 19 Nov 2013 10:41:49 +0100
Subject: [PATCH] Bug 940262 - [Australis] Hide .tab-background in the early
 tabopen animation phase and show it after a short offset r=dao

From b7ac00600af262042d076ba5ac04138eb4ee0418 Mon Sep 17 00:00:00 2001
---
 browser/base/content/browser.css    | 13 +++++++++++++
 browser/base/content/tabbrowser.xml |  2 +-
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/browser/base/content/browser.css b/browser/base/content/browser.css
index 9b546c01d49e..fad2b682ee7f 100644
--- a/browser/base/content/browser.css
+++ b/browser/base/content/browser.css
@@ -119,6 +119,19 @@ tabbrowser {
               max-width 230ms ease-out;
 }
 
+.tab-background {
+  /* Explicitly set the visibility to override the value (collapsed)
+   * we inherit from #TabsToolbar[collapsed] upon opening a browser window. */
+  visibility: visible;
+  /* This transition is only applied when opening a new tab. Closing tabs
+   * are just hidden so we don't need to adjust the delay for that. */
+  transition: visibility 0ms 25ms;
+}
+
+.tab-background[selected]:not([fadein]):not([pinned]) {
+  visibility: hidden;
+}
+
 .tab-throbber:not([fadein]):not([pinned]),
 .tab-label:not([fadein]):not([pinned]),
 .tab-icon-image:not([fadein]):not([pinned]),
diff --git a/browser/base/content/tabbrowser.xml b/browser/base/content/tabbrowser.xml
index 98735de61cbe..40d1233bd3fc 100644
--- a/browser/base/content/tabbrowser.xml
+++ b/browser/base/content/tabbrowser.xml
@@ -4643,7 +4643,7 @@
 
     <content context="tabContextMenu" closetabtext="&closeTab.label;">
       <xul:stack class="tab-stack" flex="1">
-        <xul:hbox xbl:inherits="pinned,selected,titlechanged"
+        <xul:hbox xbl:inherits="pinned,selected,titlechanged,fadein"
                   class="tab-background">
           <xul:hbox xbl:inherits="pinned,selected,titlechanged"
                     class="tab-background-start"/>