Convert TrackedPreferenceValidationDelegate into a mojo interface.

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 4d023665ec08612de0a09007b56f2d3fbe18ab63..c79ef0b012208d333caecad642f4c34eccb0803e 100644
--- a/chrome/browser/prefs/profile_pref_store_manager.h
+++ b/chrome/browser/prefs/profile_pref_store_manager.h
@@ -20,13 +20,18 @@ class HashStoreContents;
 class PersistentPrefStore;
 class PrefHashStore;
 class PrefService;
-class TrackedPreferenceValidationDelegate;
 
 namespace base {
 class DictionaryValue;
 class SequencedTaskRunner;
 }  // namespace base
 
+namespace prefs {
+namespace mojom {
+class TrackedPreferenceValidationDelegate;
+}
+}
+
 namespace user_prefs {
 class PrefRegistrySyncable;
 }  // namespace user_prefs
@@ -86,7 +91,7 @@ class ProfilePrefStoreManager {
   PersistentPrefStore* CreateProfilePrefStore(
       const scoped_refptr<base::SequencedTaskRunner>& io_task_runner,
       const base::Closure& on_reset_on_load,
-      TrackedPreferenceValidationDelegate* validation_delegate);
+      prefs::mojom::TrackedPreferenceValidationDelegate* validation_delegate);
 
   // Initializes the preferences for the managed profile with the preference
   // values in |master_prefs|. Acts synchronously, including blocking IO.