ui: Fix clang warnings about missing virtual and OVERRIDE annotations.

ui/base/animation/animation_container_unittest.cc

 // Copyright (c) 2011 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 "base/memory/scoped_ptr.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/base/animation/animation_container.h"
 #include "ui/base/animation/animation_container_observer.h"
 #include "ui/base/animation/linear_animation.h"
@@ skipping 15 matching lines @@
  private:
   DISALLOW_COPY_AND_ASSIGN(MockObserver);
 };
 
 class TestAnimation : public LinearAnimation {
  public:
   explicit TestAnimation(AnimationDelegate* delegate)
       : LinearAnimation(20, 20, delegate) {
   }
 
-  virtual void AnimateToState(double state) {
+  virtual void AnimateToState(double state) OVERRIDE {
   }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(TestAnimation);
 };
 
 }  // namespace
 
 class AnimationContainerTest: public testing::Test {
  private:
@@ skipping 70 matching lines @@
   // The timer should have finished.
   EXPECT_TRUE(delegate1.finished());
 
   // And the container should no longer be running.
   EXPECT_FALSE(container->is_running());
 
   container->set_observer(NULL);
 }
 
 }  // namespace ui