Add PPB_VarDictionary_Dev support - part 1.

ppapi/shared_impl/scoped_pp_var.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ppapi/shared_impl/scoped_pp_var.h"
 
 #include "ppapi/shared_impl/ppapi_globals.h"
 #include "ppapi/shared_impl/var_tracker.h"
 
 namespace ppapi {
@@ skipping 29 matching lines @@
   CallRelease(var_);
 }
 
 ScopedPPVar& ScopedPPVar::operator=(const PP_Var& v) {
   CallAddRef(v);
   CallRelease(var_);
   var_ = v;
   return *this;
 }
 
+PP_Var ScopedPPVar::Release() {
+  PP_Var result = var_;
+  var_ = PP_MakeUndefined();
+  return result;
+}
+
 }  // namespace ppapi