Introduces message_center_switches.(h|cc)

The new flag is --enable-new-message-center-popup, due to the discussion of crbug.com/164598
The user code: https://codereview.chromium.org/11773004/

BUG=161052
TEST=None

Review URL: https://codereview.chromium.org/11773003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@175624 0039d316-1c4b-4281-b951-d872f2087c98

ui/message_center/message_center.gyp

@@ -36,6 +36,8 @@
         'message_center_constants.cc',
         'message_center_constants.h',
         'message_center_export.h',
+        'message_center_switches.cc',
+        'message_center_switches.h',
         'message_popup_bubble.cc',
         'message_popup_bubble.h',
         'message_simple_view.cc',

ui/message_center/message_center_switches.cc

+// Copyright (c) 2012 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.
+
+#include "ui/message_center/message_center_switches.h"
+
+namespace message_center {
+namespace switches {
+
+const char kEnableNewMessageCenterBubble[] = "enable-new-message-center-bubble";
+
+}  // namespace switches
+}  // namespace message_center

ui/message_center/message_center_switches.h

+// Copyright (c) 2012 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 UI_MESSAGE_CENTER_MESSAGE_CENTER_SWITCHES_H_
+#define UI_MESSAGE_CENTER_MESSAGE_CENTER_SWITCHES_H_
+
+#include "ui/message_center/message_center_export.h"
+
+namespace message_center {
+namespace switches {
+
+MESSAGE_CENTER_EXPORT extern const char kEnableNewMessageCenterBubble[];
+
+}  // namespace switches
+}  // namespace message_center
+
+#endif  // UI_MESSAGE_CENTER_MESSAGE_CENTER_CONSTANTS_H_