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

Source/core/page/EventHandler.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2012 Digia Plc. and/or its subsidiary(-ies)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 1181 matching lines @@
     return view ? view->windowToContents(windowPoint) : windowPoint;
 }
 
 bool EventHandler::handleMousePressEvent(const PlatformMouseEvent& mouseEvent)
 {
     TRACE_EVENT0("webkit", "EventHandler::handleMousePressEvent");
 
     RefPtr<FrameView> protector(m_frame->view());
 
     UserGestureIndicator gestureIndicator(DefinitelyProcessingUserGesture);
-    m_frame->tree().top()->eventHandler().m_lastMouseDownUserGestureToken = gestureIndicator.currentToken();
+    m_frame->localFrameRoot()->eventHandler().m_lastMouseDownUserGestureToken = gestureIndicator.currentToken();
 
     cancelFakeMouseMoveEvent();
     if (m_eventHandlerWillResetCapturingMouseEventsNode)
         m_capturingMouseEventsNode = nullptr;
     m_mousePressed = true;
     m_capturesDragging = true;
     setLastKnownMousePosition(mouseEvent);
     m_mouseDownTimestamp = mouseEvent.timestamp();
     m_mouseDownMayStartDrag = false;
     m_mouseDownMayStartSelect = false;
@@ skipping 295 matching lines @@
 bool EventHandler::handleMouseReleaseEvent(const PlatformMouseEvent& mouseEvent)
 {
     TRACE_EVENT0("webkit", "EventHandler::handleMouseReleaseEvent");
 
     RefPtr<FrameView> protector(m_frame->view());
 
     m_frame->selection().setCaretBlinkingSuspended(false);
 
     OwnPtr<UserGestureIndicator> gestureIndicator;
 
-    if (m_frame->tree().top()->eventHandler().m_lastMouseDownUserGestureToken)
+    if (m_frame->localFrameRoot()->eventHandler().m_lastMouseDownUserGestureToken)
         gestureIndicator = adoptPtr(new UserGestureIndicator(m_frame->tree().top()->eventHandler().m_lastMouseDownUserGestureToken.release()));
     else
         gestureIndicator = adoptPtr(new UserGestureIndicator(DefinitelyProcessingUserGesture));
 
 #if OS(WIN)
     if (Page* page = m_frame->page())
         page->autoscrollController().handleMouseReleaseForPanScrolling(m_frame, mouseEvent);
 #endif
 
     m_mousePressed = false;
@@ skipping 2258 matching lines @@
 unsigned EventHandler::accessKeyModifiers()
 {
 #if OS(MACOSX)
     return PlatformEvent::CtrlKey | PlatformEvent::AltKey;
 #else
     return PlatformEvent::AltKey;
 #endif
 }
 
 } // namespace WebCore