Remove parts of //cc we aren't using

cc/animation/scrollbar_animation_controller_thinning.h

-// Copyright 2013 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_SCROLLBAR_ANIMATION_CONTROLLER_THINNING_H_
-#define CC_ANIMATION_SCROLLBAR_ANIMATION_CONTROLLER_THINNING_H_
-
-#include "base/memory/scoped_ptr.h"
-#include "cc/animation/scrollbar_animation_controller.h"
-#include "cc/base/cc_export.h"
-
-namespace cc {
-class LayerImpl;
-
-// Scrollbar animation that partially fades and thins after an idle delay,
-// and reacts to mouse movements.
-class CC_EXPORT ScrollbarAnimationControllerThinning
-    : public ScrollbarAnimationController {
- public:
-  static scoped_ptr<ScrollbarAnimationControllerThinning> Create(
-      LayerImpl* scroll_layer,
-      ScrollbarAnimationControllerClient* client,
-      base::TimeDelta delay_before_starting,
-      base::TimeDelta resize_delay_before_starting,
-      base::TimeDelta duration);
-
-  ~ScrollbarAnimationControllerThinning() override;
-
-  void set_mouse_move_distance_for_test(float distance) {
-    mouse_move_distance_to_trigger_animation_ = distance;
-  }
-  bool mouse_is_over_scrollbar() const { return mouse_is_over_scrollbar_; }
-  bool mouse_is_near_scrollbar() const { return mouse_is_near_scrollbar_; }
-
-  void DidScrollUpdate(bool on_resize) override;
-  void DidMouseMoveOffScrollbar() override;
-  void DidMouseMoveNear(float distance) override;
-
- protected:
-  ScrollbarAnimationControllerThinning(
-      LayerImpl* scroll_layer,
-      ScrollbarAnimationControllerClient* client,
-      base::TimeDelta delay_before_starting,
-      base::TimeDelta resize_delay_before_starting,
-      base::TimeDelta duration);
-
-  void RunAnimationFrame(float progress) override;
-
- private:
-  // Describes whether the current animation should INCREASE (darken / thicken)
-  // a bar or DECREASE it (lighten / thin).
-  enum AnimationChange {
-    NONE,
-    INCREASE,
-    DECREASE
-  };
-  float OpacityAtAnimationProgress(float progress);
-  float ThumbThicknessScaleAtAnimationProgress(float progress);
-  float AdjustScale(float new_value,
-                    float current_value,
-                    AnimationChange animation_change);
-  void ApplyOpacityAndThumbThicknessScale(float opacity,
-                                          float thumb_thickness_scale);
-
-  bool mouse_is_over_scrollbar_;
-  bool mouse_is_near_scrollbar_;
-  // Are we narrowing or thickening the bars.
-  AnimationChange thickness_change_;
-  // Are we darkening or lightening the bars.
-  AnimationChange opacity_change_;
-  // How close should the mouse be to the scrollbar before we thicken it.
-  float mouse_move_distance_to_trigger_animation_;
-
-  DISALLOW_COPY_AND_ASSIGN(ScrollbarAnimationControllerThinning);
-};
-
-}  // namespace cc
-
-#endif  // CC_ANIMATION_SCROLLBAR_ANIMATION_CONTROLLER_THINNING_H_