[blimp] Add SkPicture caching support.

cc/playback/compositing_display_item.h

Index: cc/playback/compositing_display_item.h
diff --git a/cc/playback/compositing_display_item.h b/cc/playback/compositing_display_item.h
index 484cb4b6c12a1dffea04216629671f9344df6b3d..0902571f8f879b9a61868eaa8eb0775f35dc223e 100644
--- a/cc/playback/compositing_display_item.h
+++ b/cc/playback/compositing_display_item.h
@@ -22,7 +22,6 @@
 class SkCanvas;
 
 namespace cc {
-class ImageSerializationProcessor;
 
 class CC_EXPORT CompositingDisplayItem : public DisplayItem {
  public:
@@ -34,9 +33,7 @@ class CC_EXPORT CompositingDisplayItem : public DisplayItem {
   explicit CompositingDisplayItem(const proto::DisplayItem& proto);
   ~CompositingDisplayItem() override;
 
-  void ToProtobuf(proto::DisplayItem* proto,
-                  ImageSerializationProcessor* image_serialization_processor)
-      const override;
+  void ToProtobuf(proto::DisplayItem* proto) const override;
   void Raster(SkCanvas* canvas,
               const gfx::Rect& canvas_target_playback_rect,
               SkPicture::AbortCallback* callback) const override;
@@ -72,9 +69,7 @@ class CC_EXPORT EndCompositingDisplayItem : public DisplayItem {
     return base::WrapUnique(new EndCompositingDisplayItem());
   }
 
-  void ToProtobuf(proto::DisplayItem* proto,
-                  ImageSerializationProcessor* image_serialization_processor)
-      const override;
+  void ToProtobuf(proto::DisplayItem* proto) const override;
   void Raster(SkCanvas* canvas,
               const gfx::Rect& canvas_target_playback_rect,
               SkPicture::AbortCallback* callback) const override;