Unify var tracking between webkit and the proxy.

ppapi/proxy/ppapi_proxy_test.cc

Index: ppapi/proxy/ppapi_proxy_test.cc
===================================================================
--- ppapi/proxy/ppapi_proxy_test.cc	(revision 95769)
+++ ppapi/proxy/ppapi_proxy_test.cc	(working copy)
@@ -148,7 +148,7 @@
 void PluginProxyTestHarness::SetUpHarness() {
   // These must be first since the dispatcher set-up uses them.
   PluginResourceTracker::SetInstanceForTest(&resource_tracker_);
-  PluginVarTracker::SetInstanceForTest(&var_tracker_);
+  resource_tracker_.set_var_tracker_test_override(&var_tracker_);
 
   plugin_dispatcher_.reset(new PluginDispatcher(
       base::Process::Current().handle(),
@@ -164,7 +164,7 @@
     bool is_client) {
   // These must be first since the dispatcher set-up uses them.
   PluginResourceTracker::SetInstanceForTest(&resource_tracker_);
-  PluginVarTracker::SetInstanceForTest(&var_tracker_);
+  resource_tracker_.set_var_tracker_test_override(&var_tracker_);
   plugin_delegate_mock_.Init(ipc_message_loop, shutdown_event);
 
   plugin_dispatcher_.reset(new PluginDispatcher(
@@ -180,7 +180,6 @@
   plugin_dispatcher_->DidDestroyInstance(pp_instance());
   plugin_dispatcher_.reset();
 
-  PluginVarTracker::SetInstanceForTest(NULL);
   PluginResourceTracker::SetInstanceForTest(NULL);
 }