ThreadableLoader::cancel should be called before loader destruction

third_party/WebKit/Source/core/loader/ThreadableLoader.h

 /*
  * 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 134 matching lines @@
     //   async failures separately
     //
     // Loading completes when one of the following methods are called:
     // - didFinishLoading()
     // - didFail()
     // - didFailAccessControlCheck()
     // - didFailRedirectCheck()
     // After any of these methods is called, the loader won't call any of the
     // ThreadableLoaderClient methods.
     //
-    // When a ThreadableLoader is destructed, any of the
-    // ThreadableLoaderClient methods is NOT called in response to the
-    // destruction either synchronously or after destruction.
+    // A user must guarantee that the loading complete before the attached
+    // client gets invalid. Also, a user must guarantee that the loading

[hiroshige, 2016/07/19 06:56:14]

nits:
s/loading complete /loading completes /
s/threadable loader/ThreadableLoader/

[yhirano, 2016/07/19 08:05:03]

Done.

+    // completes before the threadable loader is destructed.
     //
     // When ThreadableLoader::cancel() is called,
     // ThreadableLoaderClient::didFail() is called with a ResourceError
     // with isCancellation() returning true, if any of didFinishLoading()
     // or didFail.*() methods have not been called yet. (didFail() may be
     // called with a ResourceError with isCancellation() returning true
     // also for cancellation happened inside the loader.)
     //
     // ThreadableLoaderClient methods:
     // - may call cancel()
     // - can destroy the ThreadableLoader instance in them (by clearing
     //   std::unique_ptr<ThreadableLoader>).
+    //
+    // A ThreadableLoader can be destructed only when the loading has already
+    // completed.

[hiroshige, 2016/07/19 06:56:14]

Is this equivalent to the comment in Lines 156--157?

[yhirano, 2016/07/19 08:05:04]

Thanks, fixed.

     static std::unique_ptr<ThreadableLoader> create(ExecutionContext&, ThreadableLoaderClient*, const ThreadableLoaderOptions&, const ResourceLoaderOptions&);
 
     // The methods on the ThreadableLoaderClient passed on create() call
     // may be called synchronous to start() call.
     virtual void start(const ResourceRequest&) = 0;
 
     // A ThreadableLoader may have a timeout specified. It is possible, in some cases, for
     // the timeout to be overridden after the request is sent (for example, XMLHttpRequests
     // may override their timeout setting after sending).
     //
     // Set a new timeout relative to the time the request started, in milliseconds.
     virtual void overrideTimeout(unsigned long timeoutMilliseconds) = 0;
 
     virtual void cancel() = 0;
 
     virtual ~ThreadableLoader() { }
 
 protected:
     ThreadableLoader() { }
 };
 
 } // namespace blink
 
 #endif // ThreadableLoader_h