Make members of Singleton<T> private and only visible to the singleton type.

chrome/browser/chromeos/browser_main_chromeos.cc

 // 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.
 
 #include "chrome/browser/chromeos/browser_main_chromeos.h"
 
+#include "base/lazy_instance.h"
 #include "base/message_loop.h"
-#include "base/singleton.h"
 
 #include <gtk/gtk.h>
 
 class MessageLoopObserver : public MessageLoopForUI::Observer {
   virtual void WillProcessEvent(GdkEvent* event) {
     // On chromeos we want to map Alt-left click to right click.
     // This code only changes presses and releases. We could decide to also
     // modify drags and crossings. It doesn't seem to be a problem right now
     // with our support for context menus (the only real need we have).
     // There are some inconsistent states both with what we have and what
@@ skipping 12 matching lines @@
       event->button.state &= ~(GDK_MOD1_MASK | GDK_BUTTON1_MASK);
       // Add the third (right) button state.
       event->button.state |= GDK_BUTTON3_MASK;
     }
   }
 
   virtual void DidProcessEvent(GdkEvent* event) {
   }
 };
 
+static base::LazyInstance<MessageLoopObserver> g_message_loop_observer(
+    base::LINKER_INITIALIZED);
+
 void BrowserMainPartsChromeos::PostMainMessageLoopStart() {
-  static Singleton<MessageLoopObserver> observer;
-
   BrowserMainPartsPosix::PostMainMessageLoopStart();
   MessageLoopForUI* message_loop = MessageLoopForUI::current();
-  message_loop->AddObserver(observer.get());
+  message_loop->AddObserver(g_message_loop_observer.Pointer());
 }
 
 // static
 BrowserMainParts* BrowserMainParts::CreateBrowserMainParts(
     const MainFunctionParams& parameters) {
   return new BrowserMainPartsChromeos(parameters);
 }