Add NULL renderer check when setting layer for a remote frame

Source/web/WebLocalFrameImpl.cpp

 /*
  * Copyright (C) 2009 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 547 matching lines @@
         return;
 
     if (frame()->remotePlatformLayer())
         GraphicsLayer::unregisterContentsLayer(frame()->remotePlatformLayer());
     if (webLayer)
         GraphicsLayer::registerContentsLayer(webLayer);
     frame()->setRemotePlatformLayer(webLayer);
     // FIXME: This should be moved to WebRemoteFrame.
     ASSERT(frame()->deprecatedLocalOwner());
     frame()->deprecatedLocalOwner()->setNeedsCompositingUpdate();
-    frame()->ownerRenderer()->layer()->updateSelfPaintingLayer();
+    if (RenderPart* renderer = frame()->ownerRenderer())
+        renderer->layer()->updateSelfPaintingLayer();
 }
 
 void WebLocalFrameImpl::setPermissionClient(WebPermissionClient* permissionClient)
 {
     m_permissionClient = permissionClient;
 }
 
 void WebLocalFrameImpl::setSharedWorkerRepositoryClient(WebSharedWorkerRepositoryClient* client)
 {
     m_sharedWorkerRepositoryClient = SharedWorkerRepositoryClientImpl::create(client);
@@ skipping 1370 matching lines @@
 {
     RefPtr<LocalFrame> frame = LocalFrame::create(&m_frameLoaderClientImpl, host, owner);
     setWebCoreFrame(frame);
     frame->tree().setName(name, fallbackName);
     // May dispatch JS events; frame may be detached after this.
     frame->init();
     return frame;
 }
 
 } // namespace blink