cc: Make DisplayItemList::Append replay into an SkPicture

ui/compositor/layer.cc

Index: ui/compositor/layer.cc
diff --git a/ui/compositor/layer.cc b/ui/compositor/layer.cc
index 34c11e3f7482729acd4225ead015b8a08ecefacd..9463e299814b1f824e9580d89d59960168e65161 100644
--- a/ui/compositor/layer.cc
+++ b/ui/compositor/layer.cc
@@ -755,7 +755,7 @@ scoped_refptr<cc::DisplayItemList> Layer::PaintContentsToDisplayList(
     const gfx::Rect& clip,
     ContentLayerClient::PaintingControlSetting painting_control) {
   TRACE_EVENT1("ui", "Layer::PaintContentsToDisplayList", "name", name_);
-  scoped_refptr<cc::DisplayItemList> list = cc::DisplayItemList::Create();
+  scoped_refptr<cc::DisplayItemList> list = cc::DisplayItemList::Create(clip);

[danakj, 2015/04/14 20:49:34]

This is weird. Maybe cc should make the DisplayItemList with the clip and give
it to PaintContentsToDisplayList? Is there a reason why this returns a refptr,
does it require the ability to decide to reuse or make a new DisplayItemList?

[ajuma, 2015/04/14 21:51:27]

Done. This approach seems a lot cleaner.

   if (delegate_) {
     // TODO(danakj): Save the invalidation on the layer and pass that down
     // instead of the |clip| here. That will break everything until View