Unify var tracking between webkit and the proxy.

ppapi/proxy/ppb_var_proxy.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/ppb_var_proxy.h"
 
 #include "ppapi/c/pp_var.h"
 #include "ppapi/c/ppb_var.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 proxy {
 
 namespace {
 
 // PPP_Var plugin --------------------------------------------------------------
 
 void AddRefVar(PP_Var var) {
-  PluginVarTracker::GetInstance()->AddRef(var);
+  PluginResourceTracker::GetInstance()->var_tracker().AddRefVar(var);
 }
 
 void ReleaseVar(PP_Var var) {
-  PluginVarTracker::GetInstance()->Release(var);
+  PluginResourceTracker::GetInstance()->var_tracker().ReleaseVar(var);
 }
 
 PP_Var VarFromUtf8(PP_Module module, const char* data, uint32_t len) {
-  PP_Var ret = {};
-  ret.type = PP_VARTYPE_STRING;
-  ret.value.as_id = PluginVarTracker::GetInstance()->MakeString(data, len);
-  return ret;
+  return StringVar::StringToPPVar(module, data, len);
 }
 
 const char* VarToUtf8(PP_Var var, uint32_t* len) {
-  const std::string* str =
-      PluginVarTracker::GetInstance()->GetExistingString(var);
+  scoped_refptr<StringVar> str(StringVar::FromPPVar(var));
   if (str) {
-    *len = static_cast<uint32_t>(str->size());
-    return str->c_str();
+    *len = static_cast<uint32_t>(str->value().size());
+    return str->value().c_str();
   }
   *len = 0;
   return NULL;
 }
 
 const PPB_Var var_interface = {
   &AddRefVar,
   &ReleaseVar,
   &VarFromUtf8,
   &VarToUtf8
@@ skipping 27 matching lines @@
 }
 
 bool PPB_Var_Proxy::OnMessageReceived(const IPC::Message& msg) {
   // All PPB_Var calls are handled locally; there is no need to send or receive
   // messages here.
   return false;
 }
 
 }  // namespace proxy
 }  // namespace pp