[Mac] Enable click-drag-release behavior in the Wrench menu's custom items.

chrome/browser/cocoa/menu_tracked_root_view.mm

Index: chrome/browser/cocoa/menu_tracked_root_view.mm
diff --git a/chrome/browser/cocoa/menu_tracked_root_view.mm b/chrome/browser/cocoa/menu_tracked_root_view.mm
new file mode 100644
index 0000000000000000000000000000000000000000..ef3c24656ca84170aa784974acb5d3bd876351c8
--- /dev/null
+++ b/chrome/browser/cocoa/menu_tracked_root_view.mm
@@ -0,0 +1,15 @@
+// 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_root_view.h"
+
+@implementation MenuTrackedRootView
+
+@synthesize menuItem = menuItem_;
+
+- (void)mouseUp:(NSEvent*)theEvent {
+  [[menuItem_ menu] cancelTracking];
+}
+
+@end