Convert HTMLFrameOwnerElement and FocusController to use Frame.

Source/core/dom/TreeScope.cpp

Index: Source/core/dom/TreeScope.cpp
diff --git a/Source/core/dom/TreeScope.cpp b/Source/core/dom/TreeScope.cpp
index 45dd8a0e991870a8dad6293ec9cfefea410871ee..50820e8bcaa67281e64f92888878de442aae3e29 100644
--- a/Source/core/dom/TreeScope.cpp
+++ b/Source/core/dom/TreeScope.cpp
@@ -351,8 +351,10 @@ Element* TreeScope::adjustedFocusedElement() const
 {
     Document& document = rootNode().document();
     Element* element = document.focusedElement();
+    // FIXME(kenrb): The toLocalFrame() cast should be removed when RemoteFrames can have FrameTrees.
+    // At that point, focusedFrameOwnerElement should take a Frame instead of a LocalFrame.
     if (!element && document.page())
-        element = focusedFrameOwnerElement(document.page()->focusController().focusedFrame(), document.frame());
+        element = focusedFrameOwnerElement(toLocalFrame(document.page()->focusController().focusedFrame()), document.frame());
     if (!element)
         return 0;