Refactors animation to allow for cleaner subclassing. I'm doing this

app/test_animation_delegate.h

 // Copyright (c) 2010 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.
 
 #ifndef APP_TEST_ANIMATION_DELEGATE_H_
 #define APP_TEST_ANIMATION_DELEGATE_H_
 
 #include "app/animation.h"
 #include "base/message_loop.h"
 
 // Trivial AnimationDelegate implementation. AnimationEnded/Canceled quit the
 // message loop.
 class TestAnimationDelegate : public AnimationDelegate {
  public:
   TestAnimationDelegate() : canceled_(false), finished_(false) {
   }
 
-  virtual void AnimationStarted(const Animation* animation) {
-  }
-
   virtual void AnimationEnded(const Animation* animation) {
     finished_ = true;
     MessageLoop::current()->Quit();
   }
 
   virtual void AnimationCanceled(const Animation* animation) {
     finished_ = true;
     canceled_ = true;
     MessageLoop::current()->Quit();
   }
 
   bool finished() const {
     return finished_;
   }
 
   bool canceled() const {
     return canceled_;
   }
 
  private:
   bool canceled_;
   bool finished_;
 
   DISALLOW_COPY_AND_ASSIGN(TestAnimationDelegate);
 };
 
 #endif  // APP_TEST_ANIMATION_DELEGATE_H_