Let AssociatedURLLoader listen to destruction of the Document used for loading

third_party/WebKit/Source/web/AssociatedURLLoader.h

 /*
  * Copyright (C) 2010, 2011 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 39 matching lines @@
     AssociatedURLLoader(RawPtr<WebLocalFrameImpl>, const WebURLLoaderOptions&);
     ~AssociatedURLLoader();
 
     // WebURLLoader methods:
     void loadSynchronously(const WebURLRequest&, WebURLResponse&, WebURLError&, WebData&) override;
     void loadAsynchronously(const WebURLRequest&, WebURLLoaderClient*) override;
     void cancel() override;
     void setDefersLoading(bool) override;
     void setLoadingTaskRunner(blink::WebTaskRunner*) override;
 
+    // Called by |m_observer| to handle destruction of the Document associated
+    // with the frame given to the constructor.
+    void documentDestroyed();
+    void disposeObserver();
+
 private:
+    class ClientAdapter;
+    class Observer;
 
-    class ClientAdapter;
+    WebURLLoaderClient* m_client;
+    WebURLLoaderOptions m_options;
 
-    Persistent<WebLocalFrameImpl> m_frameImpl;
-    WebURLLoaderOptions m_options;
-    WebURLLoaderClient* m_client;
+    // An adapter which converts the DocumentThreadableLoaderClient method
+    // calls into the WebURLLoaderClient method calls.
     OwnPtr<ClientAdapter> m_clientAdapter;
     OwnPtr<DocumentThreadableLoader> m_loader;
+
+    // A ContextLifecycleObserver for cancelling |m_loader| when the Document
+    // is detached.
+    Persistent<Observer> m_observer;
 };
 
 } // namespace blink
 
 #endif