Reverting this CL because it was committed before I gave the final LGTM.

chrome/browser/chromeos/accessibility/magnification_manager.cc

Index: chrome/browser/chromeos/accessibility/magnification_manager.cc
===================================================================
--- chrome/browser/chromeos/accessibility/magnification_manager.cc	(revision 162209)
+++ chrome/browser/chromeos/accessibility/magnification_manager.cc	(working copy)
@@ -1,134 +0,0 @@
-// 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 "chrome/browser/chromeos/accessibility/magnification_manager.h"
-
-#include "ash/magnifier/magnification_controller.h"
-#include "ash/shell.h"
-#include "base/memory/scoped_ptr.h"
-#include "base/memory/singleton.h"
-#include "chrome/browser/api/prefs/pref_change_registrar.h"
-#include "chrome/browser/api/prefs/pref_member.h"
-#include "chrome/browser/chromeos/login/user_manager.h"
-#include "chrome/browser/prefs/pref_service.h"
-#include "chrome/browser/profiles/profile.h"
-#include "chrome/browser/profiles/profile_manager.h"
-#include "chrome/common/chrome_notification_types.h"
-#include "chrome/common/pref_names.h"
-#include "content/public/browser/notification_observer.h"
-#include "content/public/browser/notification_observer.h"
-#include "content/public/browser/notification_registrar.h"
-#include "content/public/browser/notification_service.h"
-
-namespace chromeos {
-
-class MagnificationManagerImpl : public MagnificationManager,
-                                 public content::NotificationObserver {
- public:
-  MagnificationManagerImpl() {
-    DCHECK(!instance_);
-    instance_ = this;
-
-    registrar_.Add(this,
-                  chrome::NOTIFICATION_SESSION_STARTED,
-                  content::NotificationService::AllSources());
-    registrar_.Add(this,
-                  chrome::NOTIFICATION_PROFILE_CREATED,
-                  content::NotificationService::AllSources());
-    registrar_.Add(this,
-                  chrome::NOTIFICATION_LOGIN_WEBUI_VISIBLE,
-                  content::NotificationService::AllSources());
-
-    Profile* profile = ProfileManager::GetDefaultProfileOrOffTheRecord();
-    SetProfile(profile);
-  }
-  virtual ~MagnificationManagerImpl() {}
-
-  static MagnificationManagerImpl* GetInstance() {
-    return instance_;
-  }
-
-  // MagnificationManager implimentation:
-  bool IsEnabled() OVERRIDE {
-    return ash::Shell::GetInstance()->magnification_controller()->IsEnabled();
-  }
-
-  void SetEnabled(bool enabled) OVERRIDE {
-    ash::Shell::GetInstance()->magnification_controller()->SetEnabled(enabled);
-  }
-
- private:
-  void SetProfile(Profile* profile) {
-    if (pref_change_registrar_) {
-      pref_change_registrar_->Remove(prefs::kScreenMagnifierEnabled, this);
-      pref_change_registrar_.reset();
-    }
-
-    if (profile) {
-      pref_change_registrar_.reset(new PrefChangeRegistrar);
-      pref_change_registrar_->Init(profile->GetPrefs());
-      pref_change_registrar_->Add(prefs::kScreenMagnifierEnabled, this);
-    }
-
-    profile_ = profile;
-    UpdateMagnifierStatus();
-  }
-
-  void UpdateMagnifierStatus() {
-    UserManager* manager = UserManager::Get();
-    if (!profile_) {
-      SetEnabled(false);
-    } else if (manager && !manager->IsSessionStarted()) {
-      SetEnabled(true);
-    } else {
-      PrefService* pref_service = profile_->GetPrefs();
-      bool enabled = pref_service->GetBoolean(prefs::kScreenMagnifierEnabled);
-      SetEnabled(enabled);
-    }
-  }
-
-  // content::NotificationObserver implimentation:
-  virtual void Observe(int type,
-                       const content::NotificationSource& source,
-                       const content::NotificationDetails& details) OVERRIDE {
-    switch (type) {
-      case chrome::NOTIFICATION_PREF_CHANGED: {
-        std::string pref = *content::Details<std::string>(details).ptr();
-        if (pref == prefs::kScreenMagnifierEnabled)
-          UpdateMagnifierStatus();
-        break;
-      }
-      case chrome::NOTIFICATION_LOGIN_WEBUI_VISIBLE:
-      case chrome::NOTIFICATION_SESSION_STARTED: {
-        Profile* profile = ProfileManager::GetDefaultProfileOrOffTheRecord();
-        SetProfile(profile);
-        break;
-      }
-    }
-  }
-
-  static MagnificationManagerImpl* instance_;
-
-  Profile* profile_;
-  content::NotificationRegistrar registrar_;
-  scoped_ptr<PrefChangeRegistrar> pref_change_registrar_;
-
-  friend struct DefaultSingletonTraits<MagnificationManagerImpl>;
-  DISALLOW_COPY_AND_ASSIGN(MagnificationManagerImpl);
-};
-
-MagnificationManagerImpl* MagnificationManagerImpl::instance_ = NULL;
-
-MagnificationManager* MagnificationManager::GetInstance() {
-  return MagnificationManagerImpl::GetInstance();
-}
-
-MagnificationManager* MagnificationManager::CreateInstance() {
-  // Makes sure that this is not called more than once.
-  CHECK(!GetInstance());
-
-  return new MagnificationManagerImpl();
-}
-
-}  // namespace chromeos