Serialize DisplayListRecordingSource to protos.

cc/test/skia_common.cc

 // 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.
 
 #include "cc/test/skia_common.h"
 
 #include "cc/playback/display_item_list.h"
 #include "skia/ext/refptr.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "third_party/skia/include/core/SkImageGenerator.h"
@@ skipping 17 matching lines @@
                      scoped_refptr<DisplayItemList> list) {
   SkImageInfo info =
       SkImageInfo::MakeN32Premul(layer_rect.width(), layer_rect.height());
   SkBitmap bitmap;
   bitmap.installPixels(info, buffer, info.minRowBytes());
   SkCanvas canvas(bitmap);
   canvas.clipRect(gfx::RectToSkRect(layer_rect));
   list->Raster(&canvas, NULL, gfx::Rect(), 1.0f);
 }
 
+bool AreDisplayListDrawingResultsSame(const gfx::Rect& layer_rect,
+                                      scoped_refptr<DisplayItemList> list_a,
+                                      scoped_refptr<DisplayItemList> list_b) {
+  const size_t pixel_size = 4 * layer_rect.size().GetArea();
+
+  scoped_ptr<unsigned char[]> pixels_a(new unsigned char[pixel_size]);
+  scoped_ptr<unsigned char[]> pixels_b(new unsigned char[pixel_size]);
+  memset(pixels_a.get(), 0, pixel_size);
+  memset(pixels_b.get(), 0, pixel_size);
+  DrawDisplayList(pixels_a.get(), layer_rect, list_a);
+  DrawDisplayList(pixels_b.get(), layer_rect, list_b);
+
+  return !memcmp(pixels_a.get(), pixels_b.get(), pixel_size);
+}
+
 skia::RefPtr<SkImage> CreateDiscardableImage(const gfx::Size& size) {
   const SkImageInfo info =
       SkImageInfo::MakeN32Premul(size.width(), size.height());
   return skia::AdoptRef(
       SkImage::NewFromGenerator(new TestImageGenerator(info)));
 }
 
 }  // namespace cc