ppapi: Remove use of MessageLoopProxy and deprecated MessageLoop APIs

ppapi/shared_impl/tracked_callback.cc

Index: ppapi/shared_impl/tracked_callback.cc
diff --git a/ppapi/shared_impl/tracked_callback.cc b/ppapi/shared_impl/tracked_callback.cc
index da0da429f73b7dde4f207de8d38971d1d9fc9329..c032a503ee8080d7ecc5fd79197543349a471692 100644
--- a/ppapi/shared_impl/tracked_callback.cc
+++ b/ppapi/shared_impl/tracked_callback.cc
@@ -6,9 +6,11 @@
 
 #include "base/bind.h"
 #include "base/compiler_specific.h"
+#include "base/location.h"
 #include "base/logging.h"
-#include "base/message_loop/message_loop.h"
+#include "base/single_thread_task_runner.h"
 #include "base/synchronization/lock.h"
+#include "base/thread_task_runner_handle.h"
 #include "ppapi/c/pp_completion_callback.h"
 #include "ppapi/c/pp_errors.h"
 #include "ppapi/c/ppb_message_loop.h"
@@ -255,7 +257,8 @@ void TrackedCallback::PostRunWithLock(int32_t result) {
       // classes protect against having a null target_loop_ otherwise).
       DCHECK(IsMainThread());
       DCHECK(PpapiGlobals::Get()->IsHostGlobals());
-      base::MessageLoop::current()->PostTask(FROM_HERE, callback_closure);
+      base::ThreadTaskRunnerHandle::Get()->PostTask(FROM_HERE,
+                                                    callback_closure);
     }
   }
   is_scheduled_ = true;