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

ui/message_center/cocoa/status_item_view_unittest.mm

Index: ui/message_center/cocoa/status_item_view_unittest.mm
diff --git a/ui/message_center/cocoa/status_item_view_unittest.mm b/ui/message_center/cocoa/status_item_view_unittest.mm
index 075e23a5d9a7829e62bb0f3d48da446314b02612..4e985b91522e287275c8d24d945cf51c856149cb 100644
--- a/ui/message_center/cocoa/status_item_view_unittest.mm
+++ b/ui/message_center/cocoa/status_item_view_unittest.mm
@@ -40,6 +40,17 @@ TEST_F(StatusItemViewTest, Callback) {
   }];
   [view_ mouseDown:nil];
   EXPECT_TRUE(got_callback);
+  [view_ mouseUp:nil];
+
+  got_callback = NO;
+  [view_ rightMouseDown:nil];
+  EXPECT_TRUE(got_callback);
+  [view_ rightMouseUp:nil];
+
+  got_callback = NO;
+  [view_ otherMouseDown:nil];
+  EXPECT_TRUE(got_callback);
+  [view_ otherMouseUp:nil];
 }
 
 TEST_F(StatusItemViewTest, UnreadCount) {