Fixed crashed when activating the context menu for toolbar buttons using Voiceover

chrome/browser/ui/cocoa/clickhold_button_cell.h

 // Copyright (c) 2011 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.
 
 #ifndef CHROME_BROWSER_UI_COCOA_CLICKHOLD_BUTTON_CELL_H_
 #define CHROME_BROWSER_UI_COCOA_CLICKHOLD_BUTTON_CELL_H_
 
 #import <Cocoa/Cocoa.h>
 
 #import "chrome/browser/ui/cocoa/image_button_cell.h"
 
 // A button cell that implements "click hold" behavior after a specified delay
 // or after dragging. If click-hold is never enabled (e.g., if
 // |-setEnableClickHold:| is never called), this behaves like a normal button.
 @interface ClickHoldButtonCell : ImageButtonCell {
  @private
   BOOL enableClickHold_;
   BOOL enableRightClick_;
   NSTimeInterval clickHoldTimeout_;
   id clickHoldTarget_;                  // Weak.
   SEL clickHoldAction_;
+  id accessibilityShowMenuTarget_;                  // Weak.
+  SEL accessibilityShowMenuAction_;
   BOOL trackOnlyInRect_;
   BOOL activateOnDrag_;
 }
 
 // Enable click-hold? Default: NO.
 @property(assign, nonatomic) BOOL enableClickHold;
 
 // Enable right click? Default: NO. Needs to be set for accessibility.
 @property(assign, nonatomic) BOOL enableRightClick;
 
 // Timeout is in seconds (at least 0.0, at most 5; 0.0 means that the button
 // will always have its click-hold action activated immediately on press).
 // Default: 0.25 (a guess at a Cocoa-ish value).
 @property(assign, nonatomic) NSTimeInterval clickHoldTimeout;
 
 // Track only in the frame rectangle? Default: NO.
 @property(assign, nonatomic) BOOL trackOnlyInRect;
 
 // Activate (click-hold) immediately on a sufficiently-large drag (if not,
 // always wait for timeout)? Default: YES.
 @property(assign, nonatomic) BOOL activateOnDrag;
 
 // Defines what to do when click-held (as per usual action/target).
 @property(assign, nonatomic) id clickHoldTarget;
 @property(assign, nonatomic) SEL clickHoldAction;
 
+// Defines what to do when the Show Menu accessibility action is performed.
+// (clickHoldAction should be independent from accessibilityShowMenuAction
+// since different operations, e.g. releasing vs. not releasing a mouse button,
+// may need to be performed for each occasion.)
+@property(assign, nonatomic) id accessibilityShowMenuTarget;
+@property(assign, nonatomic) SEL accessibilityShowMenuAction;
+
 @end  // @interface ClickHoldButtonCell
 
 #endif  // CHROME_BROWSER_UI_COCOA_CLICKHOLD_BUTTON_CELL_H_