[Media Galleries] Move RemovableStorageInfo notifications to chrome namespace (part 2)

chrome/browser/system_monitor/removable_storage_notifications.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 "chrome/browser/system_monitor/removable_storage_notifications.h"
 
 #include "base/stl_util.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/system_monitor/removable_storage_observer.h"
 
 namespace chrome {
 
+static RemovableStorageNotifications*
+    g_removable_storage_notifications = NULL;
+
 RemovableStorageNotifications::StorageInfo::StorageInfo() {
 }
 
 RemovableStorageNotifications::StorageInfo::StorageInfo(
     const std::string& id,
     const string16& device_name,
     const FilePath::StringType& device_location)
     : device_id(id),
       name(device_name),
       location(device_location) {
 }
 
 RemovableStorageNotifications::RemovableStorageNotifications()
     : observer_list_(
           new ObserverListThreadSafe<RemovableStorageObserver>()) {
+  DCHECK(!g_removable_storage_notifications);
+  g_removable_storage_notifications = this;
 }
 
 RemovableStorageNotifications::~RemovableStorageNotifications() {
+  DCHECK_EQ(this, g_removable_storage_notifications);
+  g_removable_storage_notifications = NULL;
 }
 
 void RemovableStorageNotifications::ProcessAttach(
     const std::string& id,
     const string16& name,
     const FilePath::StringType& location) {
   StorageInfo info(id, name, location);
   {
     base::AutoLock lock(storage_lock_);
     if (ContainsKey(storage_map_, id)) {
@@ skipping 42 matching lines @@
 
 void RemovableStorageNotifications::AddObserver(RemovableStorageObserver* obs) {
   observer_list_->AddObserver(obs);
 }
 
 void RemovableStorageNotifications::RemoveObserver(
     RemovableStorageObserver* obs) {
   observer_list_->RemoveObserver(obs);
 }
 
+RemovableStorageNotifications* RemovableStorageNotifications::GetInstance() {
+  return g_removable_storage_notifications;
+}
+
 }  // namespace chrome