Pref service: add support for tracked prefs.

chrome/browser/prefs/profile_pref_store_manager.h

Index: chrome/browser/prefs/profile_pref_store_manager.h
diff --git a/chrome/browser/prefs/profile_pref_store_manager.h b/chrome/browser/prefs/profile_pref_store_manager.h
index c79ef0b012208d333caecad642f4c34eccb0803e..4e32201a5ec94451be34ea3b8b2771a29a447cd5 100644
--- a/chrome/browser/prefs/profile_pref_store_manager.h
+++ b/chrome/browser/prefs/profile_pref_store_manager.h
@@ -89,7 +89,7 @@ class ProfilePrefStoreManager {
   // An optional |validation_delegate| will be notified
   // of the status of each tracked preference as they are checked.
   PersistentPrefStore* CreateProfilePrefStore(
-      const scoped_refptr<base::SequencedTaskRunner>& io_task_runner,
+      scoped_refptr<base::SequencedTaskRunner> io_task_runner,
       const base::Closure& on_reset_on_load,
       prefs::mojom::TrackedPreferenceValidationDelegate* validation_delegate);
 
@@ -106,11 +106,8 @@ class ProfilePrefStoreManager {
 
  private:
   // Returns a PrefHashStore for the managed profile. Should only be called
-  // if |kPlatformSupportsPreferenceTracking|. |use_super_mac| determines
-  // whether the returned object will calculate, store, and validate super MACs
-  // (and, by extension, accept non-null newly protected preferences as
-  // TrustedInitialized).
-  std::unique_ptr<PrefHashStore> GetPrefHashStore(bool use_super_mac);
+  // if |kPlatformSupportsPreferenceTracking|.
+  std::unique_ptr<PrefHashStore> GetPrefHashStore();
 
   // Returns a PrefHashStore and HashStoreContents which can be be used for
   // extra out-of-band verifications, or nullptrs if not available on this