Attempt four at landing the "histogram.h removed from message_loop.h" patch.

app/animation_container_unittest.cc

 // 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.
 
 #include "app/animation_container.h"
 #include "app/linear_animation.h"
 #include "app/test_animation_delegate.h"
+#include "base/scoped_ptr.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 using testing::AtLeast;
 
 namespace {
 
 class MockObserver : public AnimationContainer::Observer {
  public:
   MockObserver() {}
 
   MOCK_METHOD1(AnimationContainerProgressed, void(AnimationContainer*));
   MOCK_METHOD1(AnimationContainerEmpty, void(AnimationContainer*));
 
  private:
   DISALLOW_COPY_AND_ASSIGN(MockObserver);
 };
 
 class TestAnimation : public LinearAnimation {
  public:
-  TestAnimation(AnimationDelegate* delegate)
+  explicit TestAnimation(AnimationDelegate* delegate)
       : LinearAnimation(20, 20, delegate) {
   }
 
   virtual void AnimateToState(double state) {
   }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(TestAnimation);
 };
 
@@ skipping 72 matching lines @@
   MessageLoop::current()->Run();
 
   // The timer should have finished.
   EXPECT_TRUE(delegate1.finished());
 
   // And the container should no longer be runnings.
   EXPECT_FALSE(container->is_running());
 
   container->set_observer(NULL);
 }