repro for crbug.com/663886

base/callback_helpers.h

Index: base/callback_helpers.h
diff --git a/base/callback_helpers.h b/base/callback_helpers.h
index 782371f6e71703059aeb6a4022a1aee785f1ad2d..de7f2ac83079ddad3339966150e9cca4a9876fe7 100644
--- a/base/callback_helpers.h
+++ b/base/callback_helpers.h
@@ -31,27 +31,26 @@ base::Callback<Sig> ResetAndReturn(base::Callback<Sig>* cb) {
 // 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);
 };