Mouse event handlers use user gesture tokens on top-level LocalFrames.

Source/core/frame/LocalFrame.h

Index: Source/core/frame/LocalFrame.h
diff --git a/Source/core/frame/LocalFrame.h b/Source/core/frame/LocalFrame.h
index 0c046866bfdf7edbe03ce31cc6ac9a97bd621229..3e96c2b72a993dcf85990ee4fac4efbd8c22a9b7 100644
--- a/Source/core/frame/LocalFrame.h
+++ b/Source/core/frame/LocalFrame.h
@@ -99,6 +99,11 @@ namespace WebCore {
 
         void didChangeVisibilityState();
 
+        // FIXME: This method is only used by EventHandler to get the highest level
+        // LocalFrame in this frame's in-process subtree. When user gesture tokens
+        // are synchronized across processes this method should be removed.
+        LocalFrame* localFrameRoot();
+
     // ======== All public functions below this point are candidates to move out of LocalFrame into another class. ========
 
         bool inScope(TreeScope*) const;