repro for crbug.com/663886

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 13 matching lines @@
 base::Callback<Sig> ResetAndReturn(base::Callback<Sig>* cb) {
   base::Callback<Sig> ret(*cb);
   cb->Reset();
   return ret;
 }
 
 // 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() {}
+  explicit ScopedClosureRunner(const Closure& closure) {}
+  ~ScopedClosureRunner() {}
 
-  ScopedClosureRunner(ScopedClosureRunner&& other);
+  ScopedClosureRunner(ScopedClosureRunner&& other) {}
 
   // Releases the current closure if it's set and replaces it with the closure
   // from |other|.
-  ScopedClosureRunner& operator=(ScopedClosureRunner&& other);
+  ScopedClosureRunner& operator=(ScopedClosureRunner&& other) {return *this;}
 
   // Calls the current closure and resets it, so it wont be called again.
-  void RunAndReset();
+  void RunAndReset() {}
 
   // Replaces closure with the new one releasing the old one without calling it.
-  void ReplaceClosure(const Closure& closure);
+  void ReplaceClosure(const Closure& closure) {}
 
   // Releases the Closure without calling.
-  Closure Release() WARN_UNUSED_RESULT;
+  Closure Release() WARN_UNUSED_RESULT {return Closure();}
 
  private:
-  Closure closure_;
 
   DISALLOW_COPY_AND_ASSIGN(ScopedClosureRunner);
 };
 
 }  // namespace base
 
 #endif  // BASE_CALLBACK_HELPERS_H_