[Media Galleries] Lazily initialize the storage monitor.

chrome/browser/media_galleries/media_file_system_registry.h

Index: chrome/browser/media_galleries/media_file_system_registry.h
diff --git a/chrome/browser/media_galleries/media_file_system_registry.h b/chrome/browser/media_galleries/media_file_system_registry.h
index 4687e7d6951cfb270dfddeabac2849dcb644fe07..3f8daeebdc5127d3136b0f4e096f2d0092b044c6 100644
--- a/chrome/browser/media_galleries/media_file_system_registry.h
+++ b/chrome/browser/media_galleries/media_file_system_registry.h
@@ -16,6 +16,7 @@
 #include "base/basictypes.h"
 #include "base/files/file_path.h"
 #include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
 #include "base/prefs/pref_change_registrar.h"
 #include "chrome/browser/media_galleries/media_galleries_preferences.h"
 #include "chrome/browser/media_galleries/mtp_device_delegate_impl.h"
@@ -73,17 +74,10 @@ class MediaFileSystemRegistry : public RemovableStorageObserver {
   // Passes to |callback| the list of media filesystem IDs and paths for a
   // given RVH. Called on the UI thread.
   void GetMediaFileSystemsForExtension(
-      const content::RenderViewHost* rvh,

[vandebo (ex-Chrome), 2013/05/22 21:40:34]

why?

[Greg Billock, 2013/05/23 00:55:59]

Needed to make a RenderViewHostObserver

+      content::RenderViewHost* rvh,
       const extensions::Extension* extension,
       const MediaFileSystemsCallback& callback);
 
-  // Returns the initialized media galleries preferences for the specified
-  // |profile|. This method should be used instead of calling
-  // MediaGalleriesPreferences directly because this method also ensures that
-  // currently attached removable devices are added to the preferences.
-  // Called on the UI thread.
-  MediaGalleriesPreferences* GetPreferences(Profile* profile);
-
   // RemovableStorageObserver implementation.
   virtual void OnRemovableStorageDetached(const StorageInfo& info) OVERRIDE;
 
@@ -92,10 +86,24 @@ class MediaFileSystemRegistry : public RemovableStorageObserver {
   // See TransientDeviceIds::GetTransientIdForDeviceId().
   uint64 GetTransientIdForDeviceId(const std::string& device_id);
 
+  // This method should be used instead of calling MediaGalleriesPreferences
+  // directly because this method also ensures that currently attached
+  // removable devices are added to the preferences.
+  // Called on the UI thread.
+  // Note: Caller must ensure that the storage monitor is initialized before
+  // calling this method.
+  virtual MediaGalleriesPreferences* GetPreferences(Profile* profile) OVERRIDE;

[vandebo (ex-Chrome), 2013/05/22 21:40:34]

I think you want to undo the changes here.

[Greg Billock, 2013/05/23 00:55:59]

Done, but the comment is edited somewhat. Put it back in the right spot.

+
  private:
   friend class TestMediaFileSystemContext;
   class MediaFileSystemContextImpl;
 
+  // Bottom half of |GetMediaFileSystemsForExtension|. Called when the
+  // storage monitor is fully initialized.
+  void GetMediaFileSystemsPostInit(const content::RenderViewHost* rvh,

[vandebo (ex-Chrome), 2013/05/22 21:40:34]

I guess this plus the dialog controller is a narrower choke point, but maybe it
would be better to ensure the storage monitor is initialized in all the media
galleries API calls.  It would make things more regular across all the APIs.

[Greg Billock, 2013/05/23 00:55:59]

Oh, I see what you're saying. Hmmm. Let me think about that. We have to do the
private APIs anyway, and it may be that sticking it in the other API call is
less invasive.

+                                   const extensions::Extension* extension,
+                                   const MediaFileSystemsCallback& callback);
+
   // Map an extension to the ExtensionGalleriesHost.
   typedef std::map<std::string /*extension_id*/,
                    scoped_refptr<ExtensionGalleriesHost> > ExtensionHostMap;
@@ -135,6 +143,8 @@ class MediaFileSystemRegistry : public RemovableStorageObserver {
 
   scoped_ptr<MediaFileSystemContext> file_system_context_;
 
+  base::WeakPtrFactory<MediaFileSystemRegistry> weak_ptr_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(MediaFileSystemRegistry);
 };