[blimp] Add SkPicture caching support.

cc/test/skia_common.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_TEST_SKIA_COMMON_H_
 #define CC_TEST_SKIA_COMMON_H_
 
 #include <memory>
 
 #include "base/memory/ref_counted.h"
 #include "third_party/skia/include/core/SkImage.h"
 #include "third_party/skia/include/core/SkRefCnt.h"
 
 namespace gfx {
 class Rect;
 class Size;
 }
 
 namespace cc {
 class DisplayItemList;
 
 void DrawDisplayList(unsigned char* buffer,
                      const gfx::Rect& layer_rect,
-                     scoped_refptr<DisplayItemList> list);
+                     scoped_refptr<const DisplayItemList> list);
 
 bool AreDisplayListDrawingResultsSame(const gfx::Rect& layer_rect,
-                                      scoped_refptr<DisplayItemList> list_a,
-                                      scoped_refptr<DisplayItemList> list_b);
+                                      const DisplayItemList* list_a,
+                                      const DisplayItemList* list_b);
 
 sk_sp<SkImage> CreateDiscardableImage(const gfx::Size& size);
 
 }  // namespace cc
 
 #endif  // CC_TEST_SKIA_COMMON_H_