cc: Remove code for drawing checkerboard quads, it's not used.

cc/quads/checkerboard_draw_quad.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_QUADS_CHECKERBOARD_DRAW_QUAD_H_
-#define CC_QUADS_CHECKERBOARD_DRAW_QUAD_H_
-
-#include "base/memory/scoped_ptr.h"
-#include "cc/base/cc_export.h"
-#include "cc/quads/draw_quad.h"
-#include "third_party/skia/include/core/SkColor.h"
-
-namespace cc {
-
-class CC_EXPORT CheckerboardDrawQuad : public DrawQuad {
- public:
-  CheckerboardDrawQuad();
-
-  void SetNew(const SharedQuadState* shared_quad_state,
-              const gfx::Rect& rect,
-              const gfx::Rect& visible_rect,
-              SkColor color,
-              float scale);
-
-  void SetAll(const SharedQuadState* shared_quad_state,
-              const gfx::Rect& rect,
-              const gfx::Rect& opaque_rect,
-              const gfx::Rect& visible_rect,
-              bool needs_blending,
-              SkColor color,
-              float scale);
-
-  SkColor color;
-  float scale;
-
-  static const CheckerboardDrawQuad* MaterialCast(const DrawQuad*);
-
- private:
-  void ExtendValue(base::trace_event::TracedValue* value) const override;
-};
-
-}  // namespace cc
-
-#endif  // CC_QUADS_CHECKERBOARD_DRAW_QUAD_H_