Add protobuf serialization to DisplayItemList

cc/playback/display_item_list.h

 // Copyright 2014 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_PLAYBACK_DISPLAY_ITEM_LIST_H_
 #define CC_PLAYBACK_DISPLAY_ITEM_LIST_H_
 
 #include "base/gtest_prod_util.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/trace_event/trace_event.h"
 #include "cc/base/cc_export.h"
 #include "cc/base/list_container.h"
 #include "cc/playback/discardable_image_map.h"
 #include "cc/playback/display_item.h"
+#include "cc/playback/display_item_list_settings.h"
 #include "skia/ext/refptr.h"
 #include "third_party/skia/include/core/SkPicture.h"
 #include "ui/gfx/geometry/rect.h"
 
 class SkCanvas;
 class SkPictureRecorder;
 
 namespace cc {
 
-class DisplayItemListSettings;
+namespace proto {
+class DisplayItemList;
+}
 
 class CC_EXPORT DisplayItemList
     : public base::RefCountedThreadSafe<DisplayItemList> {
  public:
   // Creates a display item list. If picture caching is used, then layer_rect
   // specifies the cull rect of the display item list (the picture will not
   // exceed this rect). If picture caching is not used, then the given rect can
   // be empty.
   // TODO(vmpstr): Maybe this cull rect can be part of the settings instead.
   static scoped_refptr<DisplayItemList> Create(
       const gfx::Rect& layer_rect,
       const DisplayItemListSettings& settings);
 
+  // Creates a DisplayItemList from a Protobuf.
+  // TODO(dtrainor): Pass in a list of possible DisplayItems to reuse
+  // (crbug.com/548434).
+  static scoped_refptr<DisplayItemList> CreateFromProto(
+      const proto::DisplayItemList& proto);
+
+  // Creates a Protobuf representing the state of this DisplayItemList.
+  // TODO(dtrainor): Don't resend DisplayItems that were already serialized
+  // (crbug.com/548434).
+  void ToProtobuf(proto::DisplayItemList* proto);
+
   void Raster(SkCanvas* canvas,
               SkPicture::AbortCallback* callback,
               const gfx::Rect& canvas_target_playback_rect,
               float contents_scale) const;
 
   // This is a fast path for use only if canvas_ is set and
   // retain_individual_display_items_ is false. This method also updates
   // is_suitable_for_gpu_rasterization_ and approximate_op_count_.
   void RasterIntoCanvas(const DisplayItem& display_item);
 
@@ skipping 47 matching lines @@
   bool needs_process_;
 #else
   bool ProcessAppendedItemsCalled() const { return true; }
 #endif
 
   ListContainer<DisplayItem> items_;
   skia::RefPtr<SkPicture> picture_;
 
   scoped_ptr<SkPictureRecorder> recorder_;
   skia::RefPtr<SkCanvas> canvas_;
-  const bool use_cached_picture_;
+  const DisplayItemListSettings settings_;
   bool retain_individual_display_items_;
 
   gfx::Rect layer_rect_;
   bool is_suitable_for_gpu_rasterization_;
   int approximate_op_count_;
 
   // Memory usage due to the cached SkPicture.
   size_t picture_memory_usage_;
 
   // Memory usage due to external data held by display items.
   size_t external_memory_usage_;
 
   DiscardableImageMap image_map_;
 
   friend class base::RefCountedThreadSafe<DisplayItemList>;
   FRIEND_TEST_ALL_PREFIXES(DisplayItemListTest, ApproximateMemoryUsage);
   DISALLOW_COPY_AND_ASSIGN(DisplayItemList);
 };
 
 }  // namespace cc
 
 #endif  // CC_PLAYBACK_DISPLAY_ITEM_LIST_H_