[Mac] Don't close the Wrench menu after using the zoom buttons if the menu was opened sticky.

chrome/browser/cocoa/menu_tracked_button.mm

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "chrome/browser/cocoa/menu_tracked_button.h"
 
 @implementation MenuTrackedButton
 
+@synthesize tracking = tracking_;
+
 - (void)mouseEntered:(NSEvent*)theEvent {
   didEnter_ = YES;
   [super mouseEntered:theEvent];
 }
 
 - (void)mouseExited:(NSEvent*)theEvent {
   didEnter_ = NO;
   tracking_ = NO;
   [super mouseExited:theEvent];
 }
 
 - (void)mouseDragged:(NSEvent*)theEvent {
   tracking_ = !didEnter_;
   [super mouseDragged:theEvent];
 }
 
 - (void)mouseUp:(NSEvent*)theEvent {
   if (!tracking_) {
     return [super mouseUp:theEvent];
   }
   [self performClick:self];
+  tracking_ = NO;
 }
 
 @end