Bug 811738: Close tabs-tray on closing last tab. [r=mfinkle].

mobile/android/base/RemoteTabs.java

@@ -71,7 +71,7 @@ public class RemoteTabs extends LinearLayout
     public void hide() {
     }
 
-    void autoHidePanel() {
+    private void autoHidePanel() {
         mTabsPanel.autoHidePanel();
     }
 

mobile/android/base/TabsTray.java

@@ -103,7 +103,7 @@ public class TabsTray extends LinearLayout
         mTabsAdapter.clear();
     }
 
-    void autoHidePanel() {
+    private void autoHidePanel() {
         mTabsPanel.autoHidePanel();
     }
 
@@ -290,6 +290,9 @@ public class TabsTray extends LinearLayout
             }
         });
 
+        if (mTabsAdapter.getCount() == 1)
+            autoHidePanel();
+
         animator.start();
     }