Serialize DisplayListRecordingSource to protos.

cc/test/fake_display_list_recording_source.h

Index: cc/test/fake_display_list_recording_source.h
diff --git a/cc/test/fake_display_list_recording_source.h b/cc/test/fake_display_list_recording_source.h
index f8e3cc17c07927b12857cce84cd7452a824a1ffb..cb526adb896ca4a4420f4bba7903ed50c94ecbdd 100644
--- a/cc/test/fake_display_list_recording_source.h
+++ b/cc/test/fake_display_list_recording_source.h
@@ -48,6 +48,10 @@ class FakeDisplayListRecordingSource : public DisplayListRecordingSource {
       bool can_use_lcd) const override;
   bool IsSuitableForGpuRasterization() const override;
 
+  void SetDisplayListUsesCachedPicture(bool use_cached_picture) {
+    client_.set_display_list_use_cached_picture(use_cached_picture);
+  }
+
   void SetRecordedViewport(const gfx::Rect& recorded_viewport) {
     recorded_viewport_ = recorded_viewport;
   }
@@ -119,6 +123,11 @@ class FakeDisplayListRecordingSource : public DisplayListRecordingSource {
 
   DisplayItemList* display_list() const { return display_list_.get(); }
 
+  // Checks that the basic properties of the |other| match |this|.  For the
+  // DisplayItemList, it checks that the painted result matches the painted
+  // result of |other|.
+  bool EqualsTo(const FakeDisplayListRecordingSource& other);
+
  private:
   FakeContentLayerClient client_;
   SkPaint default_paint_;