[Mac][MC] Allow right click to open the message center tray.

ui/message_center/cocoa/status_item_view_unittest.mm

 // Copyright (c) 2013 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 "ui/message_center/cocoa/status_item_view.h"
 
 #include "base/memory/scoped_nsobject.h"
 #import "ui/base/test/ui_cocoa_test_helper.h"
 
 class StatusItemViewTest : public ui::CocoaTest {
@@ skipping 22 matching lines @@
 
 // These tests are like TEST_VIEW() but set some of the properties.
 
 TEST_F(StatusItemViewTest, Callback) {
   __block BOOL got_callback = NO;
   [view_ setCallback:^{
       got_callback = YES;
   }];
   [view_ mouseDown:nil];
   EXPECT_TRUE(got_callback);
+
+  got_callback = NO;
+  [view_ rightMouseDown:nil];
+  EXPECT_TRUE(got_callback);
 }
 
 TEST_F(StatusItemViewTest, UnreadCount) {
   [view_ setUnreadCount:2];
   [view_ display];
   [view_ setUnreadCount:10];
   [view_ display];
   [view_ setUnreadCount:0];
   [view_ display];
   [view_ setUnreadCount:1000];
@@ skipping 10 matching lines @@
 TEST_F(StatusItemViewTest, HighlightAndMouseEvent) {
   [view_ mouseDown:nil];
   [view_ display];
   [view_ setHighlight:YES];
   [view_ display];
   [view_ mouseUp:nil];
   [view_ display];
   [view_ setHighlight:NO];
   [view_ display];
 }