Fix PrepareTextureCopyOutputResult to avoid ScopedCallbackRunner.

base/callback_helpers.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This defines helpful methods for dealing with Callbacks.  Because Callbacks
 // are implemented using templates, with a class per callback signature, adding
 // methods to Callback<> itself is unattractive (lots of extra code gets
 // generated).  Instead, consider adding methods here.
 //
 // ResetAndReturn(&cb) is like cb.Reset() but allows executing a callback (via a
@@ skipping 19 matching lines @@
 // ScopedClosureRunner is akin to std::unique_ptr<> for Closures. It ensures
 // that the Closure is executed no matter how the current scope exits.
 class BASE_EXPORT ScopedClosureRunner {
  public:
   ScopedClosureRunner();
   explicit ScopedClosureRunner(const Closure& closure);
   ~ScopedClosureRunner();
 
   ScopedClosureRunner(ScopedClosureRunner&& other);
 
-  // Calls the current closure if it's set and replaces it with the closure from
-  // |other|.
+  // Releases the current closure if it's set and replaces it with the closure
+  // from |other|.
   ScopedClosureRunner& operator=(ScopedClosureRunner&& other);
 
   // Calls the current closure and resets it, so it wont be called again.
-  void Reset();
+  void RunAndReset();
 
-  // Calls the current closure and replaces it with the new one.
-  void Reset(const Closure& closure);
+  // Replaces closure with the new one releasing the old one without calling it.
+  void ReplaceClosure(const Closure& closure);
 
   // Releases the Closure without calling.
   Closure Release() WARN_UNUSED_RESULT;
 
  private:
   Closure closure_;
 
   DISALLOW_COPY_AND_ASSIGN(ScopedClosureRunner);
 };
 
 }  // namespace base
 
 #endif  // BASE_CALLBACK_HELPERS_H_