Raster display item lists via a visual rect RTree.

cc/blink/web_content_layer_impl.cc

Index: cc/blink/web_content_layer_impl.cc
diff --git a/cc/blink/web_content_layer_impl.cc b/cc/blink/web_content_layer_impl.cc
index cf6e344d1d63a685bd9a5e9866f8a77786266bd3..c5068f16a263c305aa6ab309a285216d02cea173 100644
--- a/cc/blink/web_content_layer_impl.cc
+++ b/cc/blink/web_content_layer_impl.cc
@@ -75,7 +75,7 @@ WebContentLayerImpl::PaintContentsToDisplayList(
   settings.use_cached_picture = UseCachedPictureRaster();
 
   scoped_refptr<cc::DisplayItemList> display_list =
-      cc::DisplayItemList::Create(PaintableRegion(), settings);

[chrishtr, 2016/07/07 19:49:22]

PaintableRegion may not start at 0,0.

[wkorman, 2016/07/12 00:00:48]

Three affected LayoutTests identified via CHECK, to investigate further:

compositing/squashing/vertical-writing-mode-squashed.html
fast/forms/huge-mac-input-clamped-width.html
fast/forms/huge-mac-input-clamped-height.html

+      cc::DisplayItemList::Create(settings);
   if (client_) {
     WebDisplayItemListImpl list(display_list.get());
     client_->paintContents(&list, PaintingControlToWeb(painting_control));