[fsp] Remember mounted file systems as soon as possible.

chrome/browser/chromeos/file_system_provider/service.h

Index: chrome/browser/chromeos/file_system_provider/service.h
diff --git a/chrome/browser/chromeos/file_system_provider/service.h b/chrome/browser/chromeos/file_system_provider/service.h
index a48fd2d7a1c1d086e0a661a53ae596e499088592..90266a1a26e447894e54a57a9ae4a6f8e0ddd17c 100644
--- a/chrome/browser/chromeos/file_system_provider/service.h
+++ b/chrome/browser/chromeos/file_system_provider/service.h
@@ -58,6 +58,11 @@ class Service : public KeyedService,
       const ProvidedFileSystemInfo& file_system_info)>
       FileSystemFactoryCallback;
 
+  // Mode of unmounting. In case of UNMOUNT_MODE_SHUTDOWN, the file system will

[hashimoto, 2014/07/02 08:59:37]

nit: How about using the term "reason" instead of "mode" to be consistent with
extensions::UnloadedExtensionInfo?

[mtomasz, 2014/07/03 05:24:07]

Good idea. Done.

+  // be remounted automatically after a reboot. In case of UNMOUNT_MODE_USER it
+  // will be permanently unmounted.
+  enum UnmountMode { UNMOUNT_MODE_USER, UNMOUNT_MODE_SHUTDOWN };

[hashimoto, 2014/07/02 08:59:37]

Is there any reason to make this enum public?
Seems UNMOUNT_MODE_SHUTDOWN is only used by Service itself and there is no
reason to allow external code to call UnmountFileSystem() with SHUTDOWN.

[mtomasz, 2014/07/03 05:24:07]

This enum is used from file_system_provider_api.cc.
Alternatively, we could have an extra method and make the enum private. However,
that method would be called only from one place. Public enum and one method is
just simpler. WDYT?

[hashimoto, 2014/07/04 06:38:41]

Public interface should be minimal to encapsulte things in each class and to
limit where to look when things get broken.
Seems in the new patch set UnmountFileSystem(SHUTDOWN) can be replaced with
UnmountFileSystem()+ForgetFileSystem().
Please remove this enum.

[mtomasz, 2014/07/04 07:50:42]

We don't want to forget on SHUTDOWN. We need to forget on USER. Hence, I don't
see an easy way to remove this enum without creating extra methods.

[hashimoto, 2014/07/07 11:07:46]

Ah, I see.
Then exposing this enum may be acceptable.

+
   Service(Profile* profile, extensions::ExtensionRegistry* extension_registry);
   virtual ~Service();
 
@@ -75,7 +80,8 @@ class Service : public KeyedService,
   // Unmounts a file system with the specified |file_system_id| for the
   // |extension_id|. For success returns true, otherwise false.
   bool UnmountFileSystem(const std::string& extension_id,
-                         const std::string& file_system_id);
+                         const std::string& file_system_id,
+                         UnmountMode mode);
 
   // Requests unmounting of the file system. The callback is called when the
   // request is accepted or rejected, with an error code. Returns false if the
@@ -128,13 +134,13 @@ class Service : public KeyedService,
   void OnRequestUnmountStatus(const ProvidedFileSystemInfo& file_system_info,
                               base::File::Error error);
 
-  // Saves a list of currently mounted file systems to preferences. Called
-  // from a destructor (on shutdown).
-  void RememberFileSystems();
+  // Remembers the file system in preferences, in order to remount after a
+  // reboot.
+  void RememberFileSystem(const ProvidedFileSystemInfo& file_system_info);
 
-  // Removes all of the file systems mounted by the |extension_id| from
-  // preferences, so they are not loaded again after reboot.
-  void ForgetFileSystems(const std::string& extension_id);
+  // Removes the file system from preferences, so it is not remounmted anymore
+  // after a reboot.
+  void ForgetFileSystem(const ProvidedFileSystemInfo& file_system_info);
 
   // Restores from preferences file systems mounted previously by the
   // |extension_id| providing extension.
@@ -147,6 +153,7 @@ class Service : public KeyedService,
   ProvidedFileSystemMap file_system_map_;  // Owns pointers.
   MountPointNameToKeyMap mount_point_name_to_key_map_;
   base::ThreadChecker thread_checker_;
+  scoped_ptr<base::DictionaryValue> file_systems_to_restore_;
   base::WeakPtrFactory<Service> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(Service);