Proper initialization for known_disabled.

chrome/browser/extensions/extension_service.cc

 // Copyright (c) 2013 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/extensions/extension_service.h"
 
 #include <algorithm>
 #include <iterator>
 #include <set>
 
@@ skipping 1414 matching lines @@
   if (!FeatureSwitch::prompt_for_external_extensions()->IsEnabled())
     return false;
 
   return (Manifest::IsExternalLocation(extension->location()) &&
           !extension_prefs_->IsExternalExtensionAcknowledged(extension->id()) &&
           !(extension_prefs_->GetDisableReasons(extension->id()) &
                 Extension::DISABLE_SIDELOAD_WIPEOUT));
 }
 
 void ExtensionService::ReconcileKnownDisabled() {
-  const ExtensionIdSet known_disabled_ids =
-      extension_prefs_->GetKnownDisabled();
-  if (known_disabled_ids.empty() && !disabled_extensions_.is_empty()) {
+  ExtensionIdSet known_disabled_ids;
+  if (!extension_prefs_->GetKnownDisabled(&known_disabled_ids)) {
     extension_prefs_->SetKnownDisabled(disabled_extensions_.GetIDs());
     UMA_HISTOGRAM_BOOLEAN("Extensions.KnownDisabledInitialized", true);
     return;
   }
 
   // Both |known_disabled_ids| and |extensions_| are ordered (by definition
   // of std::map and std::set). Iterate forward over both sets in parallel
   // to find matching IDs and disable the corresponding extensions.
   ExtensionSet::const_iterator extensions_it = extensions_.begin();
   ExtensionIdSet::const_iterator known_disabled_ids_it =
@@ skipping 1363 matching lines @@
 }
 
 void ExtensionService::AddUpdateObserver(extensions::UpdateObserver* observer) {
   update_observers_.AddObserver(observer);
 }
 
 void ExtensionService::RemoveUpdateObserver(
     extensions::UpdateObserver* observer) {
   update_observers_.RemoveObserver(observer);
 }