Implement handlified String::Equals and Name::Equals.

src/factory.cc

Index: src/factory.cc
diff --git a/src/factory.cc b/src/factory.cc
index 866a6556abcced8b2821da2c7ce75c101852c893..62888152918c1d1c1dc91d8cc90c33959f86714e 100644
--- a/src/factory.cc
+++ b/src/factory.cc
@@ -1981,10 +1981,9 @@ void Factory::ConfigureInstance(Handle<FunctionTemplateInfo> desc,
 
 
 Handle<Object> Factory::GlobalConstantFor(Handle<String> name) {
-  Heap* h = isolate()->heap();
-  if (name->Equals(h->undefined_string())) return undefined_value();
-  if (name->Equals(h->nan_string())) return nan_value();
-  if (name->Equals(h->infinity_string())) return infinity_value();
+  if (String::Equals(name, undefined_string())) return undefined_value();
+  if (String::Equals(name, nan_string())) return nan_value();
+  if (String::Equals(name, infinity_string())) return infinity_value();
   return Handle<Object>::null();
 }