Bug 1400831 - Use a shorter tab-drop-indicator image to fit both default and compact themes, and move its box-align to CSS. r=dao

* Fix shadow overlap and re-optimize w. pngcrush and optipng w. -strip all to remove metadata

MozReview-Commit-ID: GJJfYMUz34q

--HG--
extra : rebase_source : 9b3869b24f163c98885cfe664002d1d23381b293

browser/base/content/tabbrowser.css

@@ -63,6 +63,10 @@ tabpanels {
   background-color: transparent;
 }
 
+.tab-drop-indicator-box {
+  -moz-box-align: end;
+}
+
 .tab-drop-indicator {
   position: relative;
   z-index: 2;

browser/base/content/tabbrowser.xml

@@ -6334,7 +6334,7 @@
     </resources>
 
     <content>
-      <xul:hbox align="end">
+      <xul:hbox class="tab-drop-indicator-box">
         <xul:image class="tab-drop-indicator" anonid="tab-drop-indicator" collapsed="true"/>
       </xul:hbox>
       <xul:arrowscrollbox anonid="arrowscrollbox" orient="horizontal" flex="1"

browser/themes/osx/browser.css

@@ -827,6 +827,10 @@ html|span.ac-emphasize-text-url {
  * Tab Drag and Drop
  */
 
+.tab-drop-indicator-box {
+  -moz-box-align: center;
+}
+
 .tab-drop-indicator {
   list-style-image: url(chrome://browser/skin/tabbrowser/tabDragIndicator.png);
   margin-top: -2px;