Remove obsolete stack trace string in a message object.

src/messages.cc

Index: src/messages.cc
diff --git a/src/messages.cc b/src/messages.cc
index 3f4484a0987e0dfb828e4f668c34c6aca3290801..0077d0309f0794b38f7c1ea77f5e11aa46d20f02 100644
--- a/src/messages.cc
+++ b/src/messages.cc
@@ -61,7 +61,6 @@ Handle<JSMessageObject> MessageHandler::MakeMessageObject(
     const char* type,
     MessageLocation* loc,
     Vector< Handle<Object> > args,
-    Handle<String> stack_trace,
     Handle<JSArray> stack_frames) {
   Factory* factory = isolate->factory();
   Handle<String> type_handle = factory->InternalizeUtf8String(type);
@@ -82,10 +81,6 @@ Handle<JSMessageObject> MessageHandler::MakeMessageObject(
     script_handle = GetScriptWrapper(loc->script());
   }
 
-  Handle<Object> stack_trace_handle = stack_trace.is_null()
-      ? Handle<Object>::cast(factory->undefined_value())
-      : Handle<Object>::cast(stack_trace);
-
   Handle<Object> stack_frames_handle = stack_frames.is_null()
       ? Handle<Object>::cast(factory->undefined_value())
       : Handle<Object>::cast(stack_frames);
@@ -96,7 +91,6 @@ Handle<JSMessageObject> MessageHandler::MakeMessageObject(
                                   start,
                                   end,
                                   script_handle,
-                                  stack_trace_handle,
                                   stack_frames_handle);
 
   return message;