PrefValueStore incorrectly DCHECK()s when handling change notification for unregistered pref.

chrome/browser/prefs/pref_value_store.cc

 // Copyright (c) 2011 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.
 
 #include "chrome/browser/prefs/pref_value_store.h"
 
 #include "chrome/browser/prefs/pref_notifier.h"
 
 PrefValueStore::PrefStoreKeeper::PrefStoreKeeper()
     : pref_value_store_(NULL),
@@ skipping 99 matching lines @@
     }
   }
   return false;
 }
 
 void PrefValueStore::NotifyPrefChanged(
     const char* path,
     PrefValueStore::PrefStoreType new_store) {
   DCHECK(new_store != INVALID_STORE);
 
-  bool changed = true;
-  // Replying that the pref has changed in case the new store is invalid may
-  // cause problems, but it's the safer choice.
-  if (new_store != INVALID_STORE) {
-    PrefStoreType controller = ControllingPrefStoreForPref(path);
-    DCHECK(controller != INVALID_STORE);
-    // If the pref is controlled by a higher-priority store, its effective value
-    // cannot have changed.
-    if (controller != INVALID_STORE &&
-        controller < new_store) {
-      changed = false;
-    }
-  }
-
-  if (changed)
+  // If the pref is controlled by a higher-priority store, its effective value
+  // cannot have changed.
+  PrefStoreType controller = ControllingPrefStoreForPref(path);
+  if (controller == INVALID_STORE || controller >= new_store)
     pref_notifier_->OnPreferenceChanged(path);
 }
 
 bool PrefValueStore::PrefValueInManagedPlatformStore(const char* name) const {
   return PrefValueInStore(name, MANAGED_PLATFORM_STORE);
 }
 
 bool PrefValueStore::PrefValueInDeviceManagementStore(const char* name) const {
   return PrefValueInStore(name, DEVICE_MANAGEMENT_STORE);
 }
@@ skipping 103 matching lines @@
 
 void PrefValueStore::CheckInitializationCompleted() {
   for (size_t i = 0; i <= PREF_STORE_TYPE_MAX; ++i) {
     scoped_refptr<PrefStore> store =
         GetPrefStore(static_cast<PrefStoreType>(i));
     if (store && !store->IsInitializationComplete())
       return;
   }
   pref_notifier_->OnInitializationCompleted();
 }