Remove parts of //cc we aren't using

cc/layers/contents_scaling_layer.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_LAYERS_CONTENTS_SCALING_LAYER_H_
-#define CC_LAYERS_CONTENTS_SCALING_LAYER_H_
-
-#include "cc/base/cc_export.h"
-#include "cc/layers/layer.h"
-
-namespace cc {
-
-// Base class for layers that need contents scale.
-// The content bounds are determined by bounds and scale of the contents.
-class CC_EXPORT ContentsScalingLayer : public Layer {
- public:
-  void CalculateContentsScale(float ideal_contents_scale,
-                              float* contents_scale_x,
-                              float* contents_scale_y,
-                              gfx::Size* content_bounds) override;
-
-  bool Update(ResourceUpdateQueue* queue,
-              const OcclusionTracker<Layer>* occlusion) override;
-
- protected:
-  ContentsScalingLayer();
-  ~ContentsScalingLayer() override;
-
-  gfx::Size ComputeContentBoundsForScale(float scale_x, float scale_y) const;
-
- private:
-  float last_update_contents_scale_x_;
-  float last_update_contents_scale_y_;
-
-  DISALLOW_COPY_AND_ASSIGN(ContentsScalingLayer);
-};
-
-}  // namespace cc
-
-#endif  // CC_LAYERS_CONTENTS_SCALING_LAYER_H__