Change background color on mac only, bug 391549.

testing/extensions/community/chrome/content/qa.xul

@@ -84,7 +84,7 @@
     <tab label="&qa.preferences.title;" id="qa-tabbar-prefs" class="tabbrowser-tab" />
     <tab label="&qa.help.title;" class="tabbrowser-tab" />
   </tabs>
-  <tabpanels>
+  <tabpanels id="qa_tabpanels">
     <tabpanel id="qa-tab-qmo"></tabpanel>
     <tabpanel id="qa-tab-litmus"></tabpanel>
     <tabpanel id="qa-tab-bugzilla"></tabpanel>

testing/extensions/community/platform/Darwin/chrome/skin/platform.css

@@ -1 +1,6 @@
-#qa-tabbar-spacer {
  width: 17px !important;
}
#qa-tabbar-qmo {
  margin-left:  10px !important;
  margin-right: 17px !important;
}
+#qa-tabbar-spacer {
  width: 17px !important;
}
#qa-tabbar-qmo {
  margin-left:  10px !important;
  margin-right: 17px !important;
}
+
+#qa_tabpanels * {
+	background-color: #ebebeb !important;
+}
+