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

chrome/browser/ui_thread_helpers.h

+// 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.
+
+#ifndef CHROME_BROWSER_UI_THREAD_HELPERS_H_
+#define CHROME_BROWSER_UI_THREAD_HELPERS_H_
+#pragma once
+
+class Task;
+
+namespace tracked_objects {
+class Location;
+}  // namespace tracked_objects
+
+namespace ui_thread_helpers {
+
+// This can be used in place of ChromeThread::PostTask(ChromeThread::UI, ...).
+// The purpose of this function is to be able to execute Chrome work alongside
+// native work when a message loop is running nested or, in the case of Mac,
+// in a different mode.  Currently this is used for updating the HostZoomMap
+// while the Wrench menu is open, allowing for the zoom display to update.  See
+// http://crbug.com/48679 for the full rationale.
+//
+// CAVEAT EMPTOR: This function's implementation is different across platforms
+// and may run the Task in a way that differs from the stock MessageLoop.  You
+// should check the behavior on all platforms if you use this.
+bool PostTaskWhileRunningMenu(const tracked_objects::Location& from_here,
+                              Task* task);
+
+}  // namespace ui_thread_helpers
+
+#endif  // CHROME_BROWSER_UI_THREAD_HELPERS_H_