Remove calls to deprecated MessageLoop methods in ppapi.

ppapi/proxy/tracked_callback_unittest.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 <stdint.h>
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/memory/ref_counted.h"
 #include "base/run_loop.h"
@@ skipping 44 matching lines @@
     }
     base::SimpleThread::Join();
   }
   void Run() override {
     ProxyAutoLock acquire;
     // Make a local copy of message_loop_ for this thread so we can interact
     // with it even after the main thread releases it.
     scoped_refptr<MessageLoopResource> message_loop(message_loop_);
     message_loop->AttachToCurrentThread();
     // Note, run releases the lock to run events.
-    message_loop->Run();
+    base::RunLoop().Run();
     message_loop->DetachFromThread();
   }
 
   MessageLoopResource* message_loop() { return message_loop_.get(); }
 
  private:
   PP_Instance instance_;
   scoped_refptr<MessageLoopResource> message_loop_;
 };
 
@@ skipping 393 matching lines @@
   resource->ReleaseRef();
   resource->CheckFinalState();
   {
     ProxyAutoLock lock;
     resource = nullptr;
   }
 }
 
 }  // namespace proxy
 }  // namespace ppapi