Switch ObserverList::size() to ObserverList::might_have_observers() Pt.1

ui/compositor/layer_animator_unittest.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/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/strings/stringprintf.h"
@@ skipping 1746 matching lines @@
 
   delegate.SetOpacityFromAnimation(0.0f);
 
   base::TimeDelta delta = base::TimeDelta::FromSeconds(1);
   LayerAnimationSequence* sequence = new LayerAnimationSequence(
       LayerAnimationElement::CreateOpacityElement(1.0f, delta));
 
   animator->StartAnimation(sequence);
 
   // |observer| should be attached to |sequence|.
-  EXPECT_EQ(static_cast<size_t>(1), sequence->observers_.size());
+  EXPECT_TRUE(sequence->observers_.might_have_observers());
 
   // Now, release |observer|
   observer.reset();
 
   // And |sequence| should no longer be attached to |observer|.
-  EXPECT_EQ(static_cast<size_t>(0), sequence->observers_.size());
+  EXPECT_FALSE(sequence->observers_.might_have_observers());
 }
 
 TEST(LayerAnimatorTest, ObserverAttachedAfterAnimationStarted) {
   scoped_refptr<LayerAnimator> animator(LayerAnimator::CreateDefaultAnimator());
   AnimationContainerElement* element = animator.get();
   animator->set_disable_timer_for_test(true);
 
   TestImplicitAnimationObserver observer(false);
   TestLayerAnimationDelegate delegate;
   animator->SetDelegate(&delegate);
@@ skipping 586 matching lines @@
 
   settings.SetPreemptionStrategy(
       LayerAnimator::ENQUEUE_NEW_ANIMATION);
   settings.SetTransitionDuration(base::TimeDelta());
   animator->SetOpacity(magic_opacity);
 
   EXPECT_EQ(start_opacity, delegate.GetOpacityForAnimation());
 }
 
 }  // namespace ui