(Part 1) Get rid of LayerController.getLayerClient()

mobile/android/base/GeckoApp.java

@@ -574,13 +574,14 @@ abstract public class GeckoApp
         }
 
         public void run() {
+            if (mLayerClient == null) {
+                return;
+            }
+
             synchronized (mLayerClient) {
                 if (!Tabs.getInstance().isSelectedTab(mThumbnailTab))
                     return;
 
-                if (getLayerController().getLayerClient() != mLayerClient)
-                    return;
-
                 HistoryEntry lastHistoryEntry = mThumbnailTab.getLastHistoryEntry();
                 if (lastHistoryEntry == null)
                     return;

mobile/android/base/gfx/LayerController.java

@@ -135,7 +135,6 @@ public class LayerController {
         mForceRedraw = true;
     }
 
-    public LayerClient getLayerClient()           { return mLayerClient; }
     public Layer getRoot()                        { return mRootLayer; }
     public LayerView getView()                    { return mView; }
     public Context getContext()                   { return mContext; }