[PPAPI] Added VarResource_Dev class.

ppapi/cpp/resource.cc

 // Copyright (c) 2010 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/cpp/resource.h"
 
 #include <algorithm>
 
 #include "ppapi/cpp/logging.h"
 #include "ppapi/cpp/module.h"
@@ skipping 34 matching lines @@
 }
 
 Resource::Resource(PassRef, PP_Resource resource) : pp_resource_(resource) {
 }
 
 void Resource::PassRefFromConstructor(PP_Resource resource) {
   PP_DCHECK(!pp_resource_);
   pp_resource_ = resource;
 }
 
+void Resource::Clear() {
+  if (is_null())
+    return;
+  Module::Get()->core()->ReleaseResource(pp_resource_);
+  pp_resource_ = 0;
+}
+
 }  // namespace pp