arc: kArcCompatibleFilesystemChosen pref to local state and integer.

chrome/browser/chromeos/arc/arc_util.h

 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_CHROMEOS_ARC_ARC_UTIL_H_
 #define CHROME_BROWSER_CHROMEOS_ARC_ARC_UTIL_H_
 
+#include <stdint.h>
+
+#include "base/callback_forward.h"
+
 // Most utility should be put in components/arc/arc_util.{h,cc}, rather than
 // here. However, some utility implementation requires other modules defined in
 // chrome/, so this file contains such utilities.
 // Note that it is not allowed to have dependency from components/ to chrome/
 // by DEPS.
 
+class AccountId;
 class Profile;
 
 namespace base {
 class FilePath;
 }
 
 namespace arc {
 
+// Values to be stored in the local state preference to keep track of the
+// filesystem encryption migration status.
+enum FileSystemCompatibilityState : int32_t {
+  // No migiration has happend, user keeps using the old file system.
+  kFileSystemIncompatible = 0,

[Junichi Uekawa, 2017/05/11 22:15:34]

what about the case that the ext4 crypto is already in use when user has created
the directory in cryptohome?

New users always get ext4 crypto file system on dircrypto capable systems now.

They get notifications ?

+  // Migration has happend. New filesystem is in use.
+  kFileSystemCompatible = 1,
+  // Migration has happend, and a notification about the fact was already shown.
+  // TODO(kinaba): This value isn't yet used until crbug.com/711095 is done.
+  kFileSystemCompatibleAndNotified = 2,
+
+  // Existing code assumes that kFileSystemIncompatible is the only state
+  // representing incompatibility and other values are all variants of
+  // "compatible" state. Be careful in the case adding a new enum value.
+};
+
 // Returns true if ARC is allowed to run for the given profile.
 // Otherwise, returns false, e.g. if the Profile is not for the primary user,
 // ARC is not available on the device, it is in the flow to set up managed
 // account creation.
 // nullptr can be safely passed to this function. In that case, returns false.
 bool IsArcAllowedForProfile(const Profile* profile);
 
 // Returns true if ARC app is allowed to show up on app list for the given
 // profile. This can be a looser condition than IsArcAllowedForProfile.
 // ARC may be temporaliry disallowed for the profile, but it may become again
@@ skipping 39 matching lines @@
 // the given |profile|.
 // TODO(hidehiko): De-couple the concept to enable ARC system and opt-in
 // to use Google Play Store. Note that there is a plan to use ARC without
 // Google Play Store, then ARC can run without opt-in.
 void SetArcPlayStoreEnabledForProfile(Profile* profile, bool enabled);
 
 // Returns whether all ARC related OptIn preferences (i.e.
 // ArcBackupRestoreEnabled and ArcLocationServiceEnabled) are managed.
 bool AreArcAllOptInPreferencesManagedForProfile(const Profile* profile);
 
-// Returns whether ARC can run on the filesystem mounted at |path|.
-// This function should run only on threads where IO operations are allowed.
-bool IsArcCompatibleFilesystem(const base::FilePath& path);
+// Checks and updates the preference value whether the underlying filesystem
+// for the profile is compatible with ARC, when necessary. After it's done (or
+// skipped), |callback| is run either synchronously or asynchronously.
+void UpdateArcFileSystemCompatibilityPrefIfNeeded(
+    const AccountId& account_id,
+    const base::FilePath& profile_path,
+    const base::Closure& callback);
 
 }  // namespace arc
 
 #endif  // CHROME_BROWSER_CHROMEOS_ARC_ARC_UTIL_H_