Do not allow creating dummy notifier id from production, for safety.

ui/message_center/cocoa/tray_controller_unittest.mm

 // Copyright 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/tray_controller.h"
 
 #include "base/mac/scoped_nsobject.h"
 #include "base/memory/scoped_ptr.h"
 #import "ui/base/test/ui_cocoa_test_helper.h"
 #include "ui/message_center/message_center.h"
 #include "ui/message_center/message_center_tray.h"
 
-namespace {
+namespace message_center {
 
 class TrayControllerTest : public ui::CocoaTest {
  public:
   virtual void SetUp() OVERRIDE {
     ui::CocoaTest::SetUp();
     message_center::MessageCenter::Initialize();
     tray_.reset(new message_center::MessageCenterTray(
         NULL, message_center::MessageCenter::Get()));
     controller_.reset(
         [[MCTrayController alloc] initWithMessageCenterTray:tray_.get()]);
@@ skipping 25 matching lines @@
   NSRect window_frame = [[controller_ window] frame];
   EXPECT_EQ(right_point.x, NSMinX(window_frame));
 
   // With little room on the right, it should open to the left.
   right_point = NSMakePoint(NSMaxX(screen_frame) - 10, y);
   [controller_ showTrayAtRightOf:right_point atLeftOf:left_point];
   window_frame = [[controller_ window] frame];
   EXPECT_EQ(left_point.x - NSWidth(window_frame), NSMinX(window_frame));
 }
 
-}  // namespace
+}  // namespace message_center