Renamed "symbols" to "internalized strings" throughout the code base,

src/messages.cc

Index: src/messages.cc
diff --git a/src/messages.cc b/src/messages.cc
index 801930d2b3f4b86b2dacb9b5ffe2ef3b5b6c6560..c31684568037054114f54872bc50b1dffdca7de0 100644
--- a/src/messages.cc
+++ b/src/messages.cc
@@ -61,7 +61,7 @@ Handle<JSMessageObject> MessageHandler::MakeMessageObject(
     Vector< Handle<Object> > args,
     Handle<String> stack_trace,
     Handle<JSArray> stack_frames) {
-  Handle<String> type_handle = FACTORY->LookupUtf8Symbol(type);
+  Handle<String> type_handle = FACTORY->InternalizeUtf8String(type);
   Handle<FixedArray> arguments_elements =
       FACTORY->NewFixedArray(args.length());
   for (int i = 0; i < args.length(); i++) {
@@ -150,7 +150,7 @@ void MessageHandler::ReportMessage(Isolate* isolate,
 
 Handle<String> MessageHandler::GetMessage(Handle<Object> data) {
   Handle<String> fmt_str =
-      FACTORY->LookupOneByteSymbol(STATIC_ASCII_VECTOR("FormatMessage"));
+      FACTORY->InternalizeOneByteString(STATIC_ASCII_VECTOR("FormatMessage"));
   Handle<JSFunction> fun =
       Handle<JSFunction>(
           JSFunction::cast(
@@ -169,7 +169,7 @@ Handle<String> MessageHandler::GetMessage(Handle<Object> data) {
                          &caught_exception);
 
   if (caught_exception || !result->IsString()) {
-    return FACTORY->LookupOneByteSymbol(STATIC_ASCII_VECTOR("<error>"));
+    return FACTORY->InternalizeOneByteString(STATIC_ASCII_VECTOR("<error>"));
   }
   Handle<String> result_string = Handle<String>::cast(result);
   // A string that has been obtained from JS code in this way is