[Mac] Use private, undocumented Carbon events to make the presentation mode animation better.

chrome/browser/ui/cocoa/presentation_mode_controller.h

Index: chrome/browser/ui/cocoa/presentation_mode_controller.h
diff --git a/chrome/browser/ui/cocoa/presentation_mode_controller.h b/chrome/browser/ui/cocoa/presentation_mode_controller.h
index 728c2da49317a9331bf8f592f4f1d1f97974c939..284e59e3a9a2abb0c611d338557a86a196842bbe 100644
--- a/chrome/browser/ui/cocoa/presentation_mode_controller.h
+++ b/chrome/browser/ui/cocoa/presentation_mode_controller.h
@@ -5,6 +5,7 @@
 #ifndef CHROME_BROWSER_UI_COCOA_PRESENTATION_MODE_CONTROLLER_H_
 #define CHROME_BROWSER_UI_COCOA_PRESENTATION_MODE_CONTROLLER_H_
 
+#include <Carbon/Carbon.h>
 #import <Cocoa/Cocoa.h>
 
 #include "base/mac/mac_util.h"
@@ -51,6 +52,10 @@
   // running.
   scoped_nsobject<DropdownAnimation> currentAnimation_;
 
+  // Carbon event handler that's used on 10.7+ to track the menu bar as it's
+  // animating in and out. Used instead of currentAnimation_.
+  EventHandlerRef menuBarTrackingHandler_;
+
   // Timers for scheduled showing/hiding of the bar (which are always done with
   // animation).
   scoped_nsobject<NSTimer> showTimer_;