Fix crash in ExtensionService::InitializePermissions().

chrome/browser/extensions/installed_loader.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/extensions/installed_loader.h"
 
 #include "base/file_path.h"
 #include "base/metrics/histogram.h"
 #include "base/stringprintf.h"
 #include "base/utf_string_conversions.h"
@@ skipping 66 matching lines @@
         info.extension_location,
         *info.extension_manifest,
         GetCreationFlags(&info),
         &error);
   } else {
     error = errors::kManifestUnreadable;
   }
 
   // Once installed, non-unpacked extensions cannot change their IDs (e.g., by
   // updating the 'key' field in their manifest).
+  // TODO(jstritar): migrate preferences when unpacked extensions change IDs.
   if (extension &&
       extension->location() != Extension::LOAD &&
       info.extension_id != extension->id()) {
     error = errors::kCannotChangeExtensionID;
     extension = NULL;
     content::RecordAction(UserMetricsAction("Extensions.IDChangedError"));
   }
 
   if (!extension) {
     extension_service_->
@@ skipping 180 matching lines @@
   if (extension_prefs_->AllowFileAccess(info->extension_id))
     flags |= Extension::ALLOW_FILE_ACCESS;
   if (extension_prefs_->IsFromWebStore(info->extension_id))
     flags |= Extension::FROM_WEBSTORE;
   if (extension_prefs_->IsFromBookmark(info->extension_id))
     flags |= Extension::FROM_BOOKMARK;
   return flags;
 }
 
 }  // namespace extensions