PPAPI: Purposely leak ProxyLock, fix shutdown race

ppapi/shared_impl/tracked_callback.cc

 // Copyright (c) 2012 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/shared_impl/tracked_callback.h"
 
 #include "base/bind.h"
 #include "base/compiler_specific.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
@@ skipping 36 matching lines @@
   // The Enter class should handle checking this for us.
 
   // TODO(dmichael): Add tracking at the instance level, for callbacks that only
   // have an instance (e.g. for MouseLock).
   if (resource) {
     tracker_ = PpapiGlobals::Get()->GetCallbackTrackerForInstance(
         resource->pp_instance());
     tracker_->Add(make_scoped_refptr(this));
   }
 
-  base::Lock* proxy_lock = PpapiGlobals::Get()->GetProxyLock();
+  base::Lock* proxy_lock = ProxyLock::Get();
   if (proxy_lock) {
     // If the proxy_lock is valid, we're running out-of-process, and locking
     // is enabled.
     if (is_blocking()) {
       // This is a blocking completion callback, so we will need a condition
       // variable for blocking & signalling the calling thread.
       operation_completed_condvar_.reset(
           new base::ConditionVariable(proxy_lock));
     } else {
       // It's a non-blocking callback, so we should have a MessageLoopResource
@@ skipping 135 matching lines @@
   // until we're done.
   scoped_refptr<TrackedCallback> thiz = this;
   completed_ = true;
   // We may not have a valid resource, in which case we're not in the tracker.
   if (resource_id_)
     tracker_->Remove(thiz);
   tracker_ = NULL;
 }
 
 }  // namespace ppapi