Convert the pp::proxy namespace to the ppapi::proxy namespace.

ppapi/proxy/plugin_var_serialization_rules.cc

 // Copyright (c) 2011 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/proxy/plugin_var_serialization_rules.h"
 
 #include "base/logging.h"
 #include "ppapi/proxy/plugin_dispatcher.h"
 #include "ppapi/proxy/plugin_resource_tracker.h"
 #include "ppapi/proxy/plugin_var_tracker.h"
 #include "ppapi/shared_impl/var.h"
 
-using ppapi::StringVar;
-
-namespace pp {
+namespace ppapi {
 namespace proxy {
 
 PluginVarSerializationRules::PluginVarSerializationRules()
     : var_tracker_(&PluginResourceTracker::GetInstance()->var_tracker()) {
 }
 
 PluginVarSerializationRules::~PluginVarSerializationRules() {
 }
 
 PP_Var PluginVarSerializationRules::SendCallerOwned(const PP_Var& var,
@@ skipping 111 matching lines @@
     var_tracker_->ReleaseHostObject(
         static_cast<PluginDispatcher*>(dispatcher), var);
   }
 }
 
 void PluginVarSerializationRules::ReleaseObjectRef(const PP_Var& var) {
   var_tracker_->ReleaseVar(var);
 }
 
 }  // namespace proxy
-}  // namespace pp
+}  // namespace ppapi