Fixing crashes in layout tests when virtual-viewport is enabled.

Source/core/frame/PinchViewport.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 489 matching lines @@
     if (graphicsLayer == m_innerViewportContainerLayer.get()) {
         name = "Inner Viewport Container Layer";
     } else if (graphicsLayer == m_pageScaleLayer.get()) {
         name =  "Page Scale Layer";
     } else if (graphicsLayer == m_innerViewportScrollLayer.get()) {
         name =  "Inner Viewport Scroll Layer";
     } else if (graphicsLayer == m_overlayScrollbarHorizontal.get()) {
         name =  "Overlay Scrollbar Horizontal Layer";
     } else if (graphicsLayer == m_overlayScrollbarVertical.get()) {
         name =  "Overlay Scrollbar Vertical Layer";
+    } else if (graphicsLayer == m_rootTransformLayer) {
+        name =  "Root Transform Layer";
     } else {
         ASSERT_NOT_REACHED();
     }
 
     return name;
 }
 
 } // namespace blink