- Create isolate specific resuable handles and use them in the hot lookup paths.

runtime/vm/handles.h

Index: runtime/vm/handles.h
===================================================================
--- runtime/vm/handles.h	(revision 24200)
+++ runtime/vm/handles.h	(working copy)
@@ -228,6 +228,7 @@
   friend class HandleScope;
   friend class Dart;
   friend class ObjectStore;
+  friend class Isolate;
   DISALLOW_ALLOCATION();
   DISALLOW_COPY_AND_ASSIGN(Handles);
 };
@@ -338,7 +339,7 @@
 #endif  // defined(DEBUG)
 
 // Macro to start a no handles scope in the code.
-#define NOHANDLESCOPE(isolate)                                                \
+#define NOHANDLESCOPE(isolate)                                                 \
     dart::NoHandleScope no_vm_internal_handles_scope_(isolate);
 
 }  // namespace dart