Change the way the ToplevelEventHandler is hooked up. It is now both a pre- and post-target event h…

ui/base/events/event_constants.h

Index: ui/base/events/event_constants.h
===================================================================
--- ui/base/events/event_constants.h	(revision 156300)
+++ ui/base/events/event_constants.h	(working copy)
@@ -227,6 +227,10 @@
 // Creates and returns no-op event.
 UI_EXPORT base::NativeEvent CreateNoopEvent();
 
+// Returns true if default post-target handling was canceled for |event| after
+// its dispatch to its target.
+UI_EXPORT bool EventCanceledDefaultHandling(const ui::Event& event);
+
 #if defined(OS_WIN)
 UI_EXPORT int GetModifiersFromACCEL(const ACCEL& accel);
 UI_EXPORT int GetModifiersFromKeyState();