Revert 222102 "Remove unsafe access hacks from ScopedPersistent."

trunk/src/chrome/renderer/extensions/messaging_bindings.cc

Index: trunk/src/chrome/renderer/extensions/messaging_bindings.cc
===================================================================
--- trunk/src/chrome/renderer/extensions/messaging_bindings.cc	(revision 222150)
+++ trunk/src/chrome/renderer/extensions/messaging_bindings.cc	(working copy)
@@ -192,13 +192,12 @@
 
     void RunCallback() {
       v8::HandleScope handle_scope(isolate_);
-      v8::Handle<v8::Function> callback = callback_.NewHandle(isolate_);
-      v8::Handle<v8::Context> context = callback->CreationContext();
+      v8::Handle<v8::Context> context = callback_->CreationContext();
       if (context.IsEmpty())
         return;
       v8::Context::Scope context_scope(context);
       WebKit::WebScopedMicrotaskSuppression suppression;
-      callback->Call(context->Global(), 0, NULL);
+      callback_->Call(context->Global(), 0, NULL);
     }
 
     extensions::ScopedPersistent<v8::Object> object_;