[Extensions] Fix thread-safety bug in PermissionsData

extensions/common/permissions/permissions_data.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 "extensions/common/permissions/permissions_data.h"
 
 #include "base/command_line.h"
 #include "content/public/common/url_constants.h"
 #include "extensions/common/constants.h"
 #include "extensions/common/error_utils.h"
@@ skipping 302 matching lines @@
     if (error)
       *error = manifest_errors::kActiveTabPermissionNotGranted;
     return false;
   }
 
   if (error)
     *error = manifest_errors::kAllURLOrActiveTabNeeded;
   return false;
 }
 
+PermissionsData::TabPermissionsMap
+PermissionsData::CopyTabSpecificPermissionsMap() const {
+  base::AutoLock auto_lock(runtime_lock_);
+  return tab_specific_permissions_;
+}
+
 scoped_refptr<const PermissionSet> PermissionsData::GetTabSpecificPermissions(
     int tab_id) const {
   base::AutoLock auto_lock(runtime_lock_);
   CHECK_GE(tab_id, 0);
   TabPermissionsMap::const_iterator iter =
       tab_specific_permissions_.find(tab_id);
   return (iter != tab_specific_permissions_.end()) ? iter->second : NULL;
 }
 
 bool PermissionsData::HasTabSpecificPermissionToExecuteScript(
@@ skipping 38 matching lines @@
     return ACCESS_WITHHELD;
 
   if (error) {
     *error = ErrorUtils::FormatErrorMessage(manifest_errors::kCannotAccessPage,
                                             document_url.spec());
   }
   return ACCESS_DENIED;
 }
 
 }  // namespace extensions