Adding @@extension_id reserved message to l10n message map for extension....

chrome/common/extensions/extension_message_filter_peer.cc

Index: chrome/common/extensions/extension_message_filter_peer.cc
===================================================================
--- chrome/common/extensions/extension_message_filter_peer.cc	(revision 39251)
+++ chrome/common/extensions/extension_message_filter_peer.cc	(working copy)
@@ -110,8 +110,8 @@
     message_sender_->Send(new ViewHostMsg_GetExtensionMessageBundle(
         extension_id, &messages));
 
-    // Save messages we got, even if they are empty, so we don't have to
-    // ask again.
+    // Save messages we got, so we don't have to ask again.
+    // Messages map is never empty, it contains at least extension_id value.
     ExtensionToL10nMessagesMap& l10n_messages_map =
         *GetExtensionToL10nMessagesMap();
     l10n_messages_map[extension_id] = messages;
@@ -119,9 +119,6 @@
     l10n_messages = GetL10nMessagesMap(extension_id);
   }
 
-  if (l10n_messages->empty())
-    return;
-
   std::string error;
   if (ExtensionMessageBundle::ReplaceMessagesWithExternalDictionary(
           *l10n_messages, &data_, &error)) {