Prevent frame from being destroyed in middle of notification.

Source/web/FrameLoaderClientImpl.cpp

 /*
  * Copyright (C) 2009, 2012 Google Inc. All rights reserved.
  * Copyright (C) 2011 Apple 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.
@@ skipping 109 matching lines @@
             if (RuntimeEnabledFeatures::deviceMotionEnabled())
                 DeviceMotionController::from(document);
             if (RuntimeEnabledFeatures::deviceOrientationEnabled())
                 DeviceOrientationController::from(document);
         }
     }
 }
 
 void FrameLoaderClientImpl::documentElementAvailable()
 {
+    RefPtr<WebFrameImpl> protector(m_webFrame);
     if (m_webFrame->client())
         m_webFrame->client()->didCreateDocumentElement(m_webFrame);
 }
 
 void FrameLoaderClientImpl::didExhaustMemoryAvailableForScript()
 {
     if (m_webFrame->client())
         m_webFrame->client()->didExhaustMemoryAvailableForScript(m_webFrame);
 }
 
@@ skipping 156 matching lines @@
 // Called when a particular resource load completes
 void FrameLoaderClientImpl::dispatchDidFinishLoading(DocumentLoader* loader,
                                                     unsigned long identifier)
 {
     if (m_webFrame->client())
         m_webFrame->client()->didFinishResourceLoad(m_webFrame, identifier);
 }
 
 void FrameLoaderClientImpl::dispatchDidFinishDocumentLoad()
 {
+    RefPtr<WebFrameImpl> protector(m_webFrame);
     if (m_webFrame->client())
         m_webFrame->client()->didFinishDocumentLoad(m_webFrame);
 }
 
 void FrameLoaderClientImpl::dispatchDidLoadResourceFromMemoryCache(const ResourceRequest& request, const ResourceResponse& response)
 {
     if (m_webFrame->client())
         m_webFrame->client()->didLoadResourceFromMemoryCache(m_webFrame, WrappedResourceRequest(request), WrappedResourceResponse(response));
 }
 
@@ skipping 429 matching lines @@
     return m_webFrame->sharedWorkerRepositoryClient();
 }
 
 void FrameLoaderClientImpl::didStopAllLoaders()
 {
     if (m_webFrame->client())
         m_webFrame->client()->didAbortLoading(m_webFrame);
 }
 
 } // namespace blink