Revert 189518 "PPAPI: Remove threading options; it's always on"

trunk/src/ppapi/proxy/plugin_resource_tracker_unittest.cc

Index: trunk/src/ppapi/proxy/plugin_resource_tracker_unittest.cc
===================================================================
--- trunk/src/ppapi/proxy/plugin_resource_tracker_unittest.cc	(revision 189681)
+++ trunk/src/ppapi/proxy/plugin_resource_tracker_unittest.cc	(working copy)
@@ -9,7 +9,6 @@
 #include "ppapi/proxy/plugin_resource_tracker.h"
 #include "ppapi/proxy/ppapi_messages.h"
 #include "ppapi/proxy/ppapi_proxy_test.h"
-#include "ppapi/shared_impl/proxy_lock.h"
 
 namespace ppapi {
 namespace proxy {
@@ -41,8 +40,6 @@
 };
 
 TEST_F(PluginResourceTrackerTest, PluginResourceForHostResource) {
-  ProxyAutoLock lock;
-
   PP_Resource host_resource = 0x5678;
 
   HostResource serialized;