Clip a layer when its render target's render surface is clipped.

cc/trees/layer_tree_host_common.cc

Index: cc/trees/layer_tree_host_common.cc
diff --git a/cc/trees/layer_tree_host_common.cc b/cc/trees/layer_tree_host_common.cc
index 6863850c97b01c7e98fac52450e1609742ec8948..6d75687201a55b640db73bb1d10ac125bdf63c5a 100644
--- a/cc/trees/layer_tree_host_common.cc
+++ b/cc/trees/layer_tree_host_common.cc
@@ -392,7 +392,7 @@ static gfx::Rect CalculateVisibleContentRect(
   gfx::Rect visible_rect_in_target_surface_space =
       layer->drawable_content_rect();
 
-  if (!layer->render_target()->render_surface()->clip_rect().IsEmpty()) {
+  if (layer->render_target()->render_surface()->is_clipped()) {

[danakj, 2014/11/26 19:05:09]

Sorry for the OOO delays. This does look better. Can you add a
LayerTreeHostCommon unit test that would fail before this change and pass after
it?

[hush (inactive), 2014/11/26 19:06:59]

Sure. I will do it in the next patch

     // The |layer| L has a target T which owns a surface Ts. The surface Ts
     // has a target TsT.
     //