Create frequently used symbols in the vm isolate

vm/class_finalizer.cc

Index: vm/class_finalizer.cc
===================================================================
--- vm/class_finalizer.cc	(revision 9729)
+++ vm/class_finalizer.cc	(working copy)
@@ -10,6 +10,7 @@
 #include "vm/longjump.h"
 #include "vm/object_store.h"
 #include "vm/parser.h"
+#include "vm/symbols.h"
 
 namespace dart {
 
@@ -341,11 +342,11 @@
     ObjectStore* object_store = Isolate::Current()->object_store();
     const Library& core_impl_lib = Library::Handle(Library::CoreImplLibrary());
     const String& integer_implementation_name =
-        String::Handle(String::NewSymbol("IntegerImplementation"));
+        String::Handle(Symbols::New("IntegerImplementation"));
     const Class& integer_implementation_class =
         Class::Handle(core_impl_lib.LookupClass(integer_implementation_name));
     const String& growable_object_array_name =
-        String::Handle(String::NewSymbol("GrowableObjectArray"));
+        String::Handle(Symbols::New("GrowableObjectArray"));
     const Class& growable_object_array_class =
         Class::Handle(core_impl_lib.LookupClass(growable_object_array_name));
     if ((super_class.raw() == object_store->bool_class()) ||