Optimize isFinite and isNaN.

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..b3f83fe98dfdb9f5d6183d3585345cc44f6487c4 100644
--- a/src/extensions/externalize-string-extension.cc
+++ b/src/extensions/externalize-string-extension.cc
@@ -133,11 +133,9 @@ v8::Handle<v8::Value> ExternalizeStringExtension::IsAscii(
 
 
 void ExternalizeStringExtension::Register() {
-  static ExternalizeStringExtension* externalize_extension = NULL;
-  if (externalize_extension == NULL)
-    externalize_extension = new ExternalizeStringExtension;
+  static ExternalizeStringExtension externalize_extension;
   static v8::DeclareExtension externalize_extension_declaration(
-      externalize_extension);
+      &externalize_extension);
 }
 
 } }  // namespace v8::internal