Remove parts of //cc we aren't using

cc/animation/layer_animation_value_observer.h

-// Copyright 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.
-
-#ifndef CC_ANIMATION_LAYER_ANIMATION_VALUE_OBSERVER_H_
-#define CC_ANIMATION_LAYER_ANIMATION_VALUE_OBSERVER_H_
-
-#include "cc/base/cc_export.h"
-
-namespace gfx {
-class ScrollOffset;
-class Transform;
-}
-
-namespace cc {
-
-class FilterOperations;
-
-class CC_EXPORT LayerAnimationValueObserver {
- public:
-  virtual ~LayerAnimationValueObserver() {}
-
-  virtual void OnFilterAnimated(const FilterOperations& filters) = 0;
-  virtual void OnOpacityAnimated(float opacity) = 0;
-  virtual void OnTransformAnimated(const gfx::Transform& transform) = 0;
-  virtual void OnScrollOffsetAnimated(
-      const gfx::ScrollOffset& scroll_offset) = 0;
-  virtual void OnAnimationWaitingForDeletion() = 0;
-  virtual bool IsActive() const = 0;
-};
-
-}  // namespace cc
-
-#endif  // CC_ANIMATION_LAYER_ANIMATION_VALUE_OBSERVER_H_