[Media Galleries] Lazily initialize the storage monitor.

chrome/browser/media_galleries/media_file_system_registry.cc

Index: chrome/browser/media_galleries/media_file_system_registry.cc
diff --git a/chrome/browser/media_galleries/media_file_system_registry.cc b/chrome/browser/media_galleries/media_file_system_registry.cc
index 88c3752ae5d316cc9e23e7577ac965b23e2babde..d9b4b1ea55edadf8fa657ca0087790485165a3e5 100644
--- a/chrome/browser/media_galleries/media_file_system_registry.cc
+++ b/chrome/browser/media_galleries/media_file_system_registry.cc
@@ -468,11 +468,12 @@ MediaGalleriesPreferences* MediaFileSystemRegistry::GetPreferences(
   // once per profile.
   extension_hosts_map_[profile] = ExtensionHostMap();
 
-  // TODO(gbillock): Move this stanza to MediaGalleriesPreferences init code.

[vandebo (ex-Chrome), 2013/05/31 18:05:03]

I think we still want to do this, leave in todo?

[Greg Billock, 2013/06/01 01:48:46]

Yeah, I think this was impossible with the getting preferences async, but may
still be doable now.

   // StorageMonitor may be NULL in unit tests.
+  // TODO(gbillock): Make sure all tests have a storage monitor and remove this.
   StorageMonitor* monitor = StorageMonitor::GetInstance();
   if (!monitor)
     return preferences;
+  DCHECK(monitor->IsInitialized());
   std::vector<StorageInfo> existing_devices = monitor->GetAttachedStorage();
   for (size_t i = 0; i < existing_devices.size(); i++) {
     if (!StorageInfo::IsMediaDevice(existing_devices[i].device_id()))