Fix a memory leak in the layer animator

ui/gfx/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/gfx/compositor/layer_animator.h"
 
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "ui/base/animation/animation_container.h"
@@ skipping 375 matching lines @@
           RemoveAnimation(sequences[i]));
       if (abort)
         sequences[i]->Abort();
       else
         sequences[i]->Progress(sequences[i]->duration(), delegate());
     }
   }
 }
 
 void LayerAnimator::ImmediatelySetNewTarget(LayerAnimationSequence* sequence) {
+  // Ensure that sequence is disposed of when this function completes.
+  scoped_ptr<LayerAnimationSequence> to_dispose(sequence);
   const bool abort = false;
   RemoveAllAnimationsWithACommonProperty(sequence, abort);
-  scoped_ptr<LayerAnimationSequence> removed(RemoveAnimation(sequence));
+  LayerAnimationSequence* removed = RemoveAnimation(sequence);
+  DCHECK(removed == NULL || removed == sequence);
   sequence->Progress(sequence->duration(), delegate());
 }
 
 void LayerAnimator::ImmediatelyAnimateToNewTarget(
     LayerAnimationSequence* sequence) {
   const bool abort = true;
   RemoveAllAnimationsWithACommonProperty(sequence, abort);
   AddToQueueIfNotPresent(sequence);
   StartSequenceImmediately(sequence);
 }
@@ skipping 114 matching lines @@
     ObserverListBase<LayerAnimationObserver>::Iterator it(observers_);
     LayerAnimationObserver* obs;
     while ((obs = it.GetNext()) != NULL) {
       sequence->AddObserver(obs);
     }
   }
   sequence->OnScheduled();
 }
 
 }  // namespace ui