Prevent ThreadableLoaderClient methods from being called after failure notification

Source/core/loader/DocumentThreadableLoader.h

 /*
  * Copyright (C) 2009, 2012 Google Inc. All rights reserved.
  * Copyright (C) 2013, Intel Corporation
  *
  * 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 55 matching lines @@
         void setDefersLoading(bool);
 
     private:
         enum BlockingBehavior {
             LoadSynchronously,
             LoadAsynchronously
         };
 
         DocumentThreadableLoader(Document&, ThreadableLoaderClient*, BlockingBehavior, const ResourceRequest&, const ThreadableLoaderOptions&, const ResourceLoaderOptions&);
 
+        void clear();
+
         // ResourceClient
         void notifyFinished(Resource*) override;
         // RawResourceClient
         void dataSent(Resource*, unsigned long long bytesSent, unsigned long long totalBytesToBeSent) override;
         void responseReceived(Resource*, const ResourceResponse&, PassOwnPtr<WebDataConsumerHandle>) override;
         void setSerializedCachedMetadata(Resource*, const char*, size_t) override;
         void dataReceived(Resource*, const char* data, unsigned dataLength) override;
         void redirectReceived(Resource*, ResourceRequest&, const ResourceResponse&) override;
         void dataDownloaded(Resource*, int) override;
         void didReceiveResourceTiming(Resource*, const ResourceTimingInfo&) override;
@@ skipping 82 matching lines @@
         // cross-origin redirects.
         // This is used to limit the number of redirects.
         // But this value is not the max number of total redirects allowed,
         // because same-origin redirects are not counted here.
         int m_corsRedirectLimit;
     };
 
 } // namespace blink
 
 #endif // DocumentThreadableLoader_h