Make ui::ThreadedTransformTransition::OnAbort correctly check whether the animation has started

ui/compositor/layer_animation_element.cc

 // 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.
 
 #include "ui/compositor/layer_animation_element.h"
 
 #include "base/compiler_specific.h"
 #include "cc/animation/animation.h"
 #include "cc/animation/animation_id_provider.h"
 #include "ui/base/animation/tween.h"
@@ skipping 499 matching lines @@
   virtual void OnStart(LayerAnimationDelegate* delegate) OVERRIDE {
     start_ = delegate->GetTransformForAnimation();
     float device_scale_factor = delegate->GetDeviceScaleFactor();
     cc_start_ = Layer::ConvertTransformToCCTransform(start_,
                                                      device_scale_factor);
     cc_target_ = Layer::ConvertTransformToCCTransform(target_,
                                                       device_scale_factor);
   }
 
   virtual void OnAbort(LayerAnimationDelegate* delegate) OVERRIDE {
-    if (delegate && animation_id()) {
+    if (delegate && Started()) {
       ThreadedLayerAnimationElement::OnAbort(delegate);
       delegate->SetTransformFromAnimation(Tween::ValueBetween(
           Tween::CalculateValue(tween_type(), last_progressed_fraction()),
           start_,
           target_));
     }
   }
 
   virtual void OnEnd(LayerAnimationDelegate* delegate) OVERRIDE {
     delegate->SetTransformFromAnimation(target_);
@@ skipping 248 matching lines @@
 }
 
 // static
 LayerAnimationElement* LayerAnimationElement::CreateColorElement(
     SkColor color,
     base::TimeDelta duration) {
   return new ColorTransition(color, duration);
 }
 
 }  // namespace ui