Changes around ascii-check for strings wrt external strings.

src/extensions/externalize-string-extension.cc

Index: src/extensions/externalize-string-extension.cc
diff --git a/src/extensions/externalize-string-extension.cc b/src/extensions/externalize-string-extension.cc
index 9fbf3298189acdace28f175af3f855b5ae13bd68..d98c586b8f53c8f8ca1570ee20b3bec68bdafa03 100644
--- a/src/extensions/externalize-string-extension.cc
+++ b/src/extensions/externalize-string-extension.cc
@@ -127,8 +127,8 @@ v8::Handle<v8::Value> ExternalizeStringExtension::IsAscii(
     return v8::ThrowException(v8::String::New(
         "isAsciiString() requires a single string argument."));
   }
-  return Utils::OpenHandle(*args[0].As<v8::String>())->IsAsciiRepresentation() ?
-      v8::True() : v8::False();
+  Handle<String> string = Utils::OpenHandle(*args[0].As<v8::String>());
+  return string->IsAsciiRepresentationUnderneath() ? v8::True() : v8::False();
 }