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

chrome/browser/system_monitor/removable_storage_notifications.cc

Index: chrome/browser/system_monitor/removable_storage_notifications.cc
diff --git a/chrome/browser/system_monitor/removable_storage_notifications.cc b/chrome/browser/system_monitor/removable_storage_notifications.cc
index 05014f86cb7abb8dae8ae9cbad329f8d4ba314fb..8520d849d4565a3efcada88d7e049692a7a79f83 100644
--- a/chrome/browser/system_monitor/removable_storage_notifications.cc
+++ b/chrome/browser/system_monitor/removable_storage_notifications.cc
@@ -10,6 +10,9 @@
 
 namespace chrome {
 
+static RemovableStorageNotifications*
+    g_removable_storage_notifications = NULL;
+
 RemovableStorageNotifications::StorageInfo::StorageInfo() {
 }
 
@@ -25,9 +28,13 @@ RemovableStorageNotifications::StorageInfo::StorageInfo(
 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(
@@ -90,4 +97,8 @@ void RemovableStorageNotifications::RemoveObserver(
   observer_list_->RemoveObserver(obs);
 }
 
+RemovableStorageNotifications* RemovableStorageNotifications::GetInstance() {
+  return g_removable_storage_notifications;
+}
+
 }  // namespace chrome