[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 f210e285e3b16aa2806da8a9f6536f77449e5b43..dbac765b3ffdc6b788d091b2d7bad5cf35e4438c 100644
--- a/chrome/browser/media_galleries/media_file_system_registry.cc
+++ b/chrome/browser/media_galleries/media_file_system_registry.cc
@@ -431,11 +431,24 @@ void MediaFileSystemRegistry::GetMediaFileSystemsForExtension(
     const content::RenderViewHost* rvh,
     const extensions::Extension* extension,
     const MediaFileSystemsCallback& callback) {
+LOG(INFO) << "GetFSForExt";
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   Profile* profile =
       Profile::FromBrowserContext(rvh->GetProcess()->GetBrowserContext());
-  MediaGalleriesPreferences* preferences = GetPreferences(profile);
+  GetPreferencesAsync(
+      profile, base::Bind(
+          &MediaFileSystemRegistry::GetMediaFileSystemsPostStorageMonitorInit,
+          base::Unretained(this),
+          rvh, extension, callback));
+}
+
+void MediaFileSystemRegistry::GetMediaFileSystemsPostStorageMonitorInit(
+    const content::RenderViewHost* rvh,
+    const extensions::Extension* extension,
+    const MediaFileSystemsCallback& callback,
+    MediaGalleriesPreferences* preferences) {
+LOG(INFO) << "GetFSForExtPostInit";
   MediaGalleryPrefIdSet galleries =
       preferences->GalleriesForExtension(*extension);
 
@@ -444,6 +457,8 @@ void MediaFileSystemRegistry::GetMediaFileSystemsForExtension(
     return;
   }
 
+  Profile* profile =
+      Profile::FromBrowserContext(rvh->GetProcess()->GetBrowserContext());
   if (!ContainsKey(pref_change_registrar_map_, profile)) {
     PrefChangeRegistrar* pref_registrar = new PrefChangeRegistrar;
     pref_registrar->Init(profile->GetPrefs());
@@ -470,8 +485,39 @@ void MediaFileSystemRegistry::GetMediaFileSystemsForExtension(
                                       callback);
 }
 
+void MediaFileSystemRegistry::GetPreferencesAsync(
+    Profile* profile,
+    base::Callback<void(MediaGalleriesPreferences*)> callback) {
+LOG(INFO) << "GetPreferencesAsync";
+  StorageMonitor* monitor = StorageMonitor::GetInstance();
+  if (!monitor) {

[Lei Zhang, 2013/05/10 05:24:43]

Do we want to just make tests that use MediaFSRegistry have a storage monitor,
instead of writing handlers for things that should never happen in production?

[Greg Billock, 2013/05/10 16:20:27]

Yes, I think that'd be better. I kind of suspect this may even be obsolete, and
all our tests really do have a storage monitor already. :-/ Let's do that
separately though.

[Lei Zhang, 2013/05/11 02:12:22]

Can you add a TODO so we don't forget?

[Greg Billock, 2013/05/13 21:20:38]

Done.

+    callback.Run(MediaGalleriesPreferencesFactory::GetForProfile(profile));
+    return;
+  }
+
+  if (monitor->IsInitialized()) {
+    callback.Run(GetPreferences(profile));
+    return;
+  }
+
+  monitor->Initialize(
+      base::Bind(&MediaFileSystemRegistry::OnStorageMonitorInitialized,
+                 base::Unretained(this),
+                 profile, callback));
+
+  // TODO(gbillock): set a timeout here to bail out of init?
+}
+
+void MediaFileSystemRegistry::OnStorageMonitorInitialized(
+    Profile* profile,
+    base::Callback<void(MediaGalleriesPreferences*)> callback) {
+LOG(INFO) << "StorageMonitor inialized...";
+  callback.Run(GetPreferences(profile));
+}
+
 MediaGalleriesPreferences* MediaFileSystemRegistry::GetPreferences(
     Profile* profile) {
+LOG(INFO) << "MFSR::GetPreferences";
   MediaGalleriesPreferences* preferences =
       MediaGalleriesPreferencesFactory::GetForProfile(profile);
   if (ContainsKey(extension_hosts_map_, profile))
@@ -485,6 +531,7 @@ MediaGalleriesPreferences* MediaFileSystemRegistry::GetPreferences(
   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 (!MediaStorageUtil::IsMediaDevice(existing_devices[i].device_id))