[WIP] Adding support for <iframe>s to slimming paint.

Source/core/frame/Frame.h

Index: Source/core/frame/Frame.h
diff --git a/Source/core/frame/Frame.h b/Source/core/frame/Frame.h
index fc2769a1e419f539ddb8b66cd2f3aeb693d4c797..c10baf2f478c470c754c4cc01845f22e9b7923bf 100644
--- a/Source/core/frame/Frame.h
+++ b/Source/core/frame/Frame.h
@@ -42,6 +42,7 @@ class FrameHost;
 class FrameOwner;
 class HTMLFrameOwnerElement;
 class LocalDOMWindow;
+class LocalFrame;
 class KURL;
 class Page;
 class RenderPart;
@@ -78,6 +79,7 @@ public:
 
     bool isMainFrame() const;
     bool isLocalRoot() const;
+    LocalFrame* localRoot() const;
 
     FrameOwner* owner() const;
     void setOwner(FrameOwner* owner) { m_owner = owner; }