compositor/layer_animator: handle delegate removal in LayerAnimation::StopAnimating

ui/compositor/layer_animator.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_animator.h"
 
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "cc/animation/animation_id_provider.h"
@@ skipping 391 matching lines @@
     if (running_animations_copy[i].sequence()->IsFinished(now)) {
       SAFE_INVOKE_VOID(FinishAnimation, running_animations_copy[i], false);
     } else {
       SAFE_INVOKE_VOID(ProgressAnimation, running_animations_copy[i], now);
     }
   }
 }
 
 void LayerAnimator::StopAnimatingInternal(bool abort) {
   scoped_refptr<LayerAnimator> retain(this);
-  while (is_animating()) {
+  while (is_animating() && delegate()) {
     // We're going to attempt to finish the first running animation. Let's
     // ensure that it's valid.
     PurgeDeletedAnimations();
 
     // If we've purged all running animations, attempt to start one up.
     if (running_animations_.empty())
       ProcessQueue();
 
     DCHECK(!running_animations_.empty());
 
@@ skipping 87 matching lines @@
 }
 
 void LayerAnimator::FinishAnimation(
     LayerAnimationSequence* sequence, bool abort) {
   scoped_refptr<LayerAnimator> retain(this);
   scoped_ptr<LayerAnimationSequence> removed(RemoveAnimation(sequence));
   if (abort)
     sequence->Abort(delegate());
   else
     ProgressAnimationToEnd(sequence);
+  if (!delegate())
+    return;
   ProcessQueue();
   UpdateAnimationState();
 }
 
 void LayerAnimator::FinishAnyAnimationWithZeroDuration() {
   scoped_refptr<LayerAnimator> retain(this);
   // Special case: if we've started a 0 duration animation, just finish it now
   // and get rid of it. We need to make a copy because Progress may indirectly
   // cause new animations to start running.
   RunningAnimations running_animations_copy = running_animations_;
@@ skipping 323 matching lines @@
 }
 
 LayerAnimator::RunningAnimation::RunningAnimation(
     const base::WeakPtr<LayerAnimationSequence>& sequence)
     : sequence_(sequence) {
 }
 
 LayerAnimator::RunningAnimation::~RunningAnimation() { }
 
 }  // namespace ui