Attach a WebLayer to a frame element for out-of-process iframes.

Source/core/rendering/RenderLayerCompositor.cpp

Index: Source/core/rendering/RenderLayerCompositor.cpp
diff --git a/Source/core/rendering/RenderLayerCompositor.cpp b/Source/core/rendering/RenderLayerCompositor.cpp
index 9eeaf039db78ccf1c014d76ef98ba54884b9191f..f80331727f49129b7165b9d2faa9cdb38b0515ca 100644
--- a/Source/core/rendering/RenderLayerCompositor.cpp
+++ b/Source/core/rendering/RenderLayerCompositor.cpp
@@ -1673,6 +1673,9 @@ bool RenderLayerCompositor::requiresCompositingForFrame(RenderObject* renderer)
     if (!frameRenderer->requiresAcceleratedCompositing())
         return false;
 
+    if (frameRenderer->isRenderIFrame() && frameRenderer->node() &&  toHTMLFrameOwnerElement(frameRenderer->node())->platformLayer())

[Charlie Reis, 2013/12/06 18:00:04]

Is isRenderIFrame() specific to iframes?  We'd like this to work for frame tags
as well.

+        return true;
+
     // FIXME: this seems bogus. If we don't know the layout position/size of the frame yet, wouldn't that be handled elsehwere?
     m_needsToRecomputeCompositingRequirements = true;