Remove use of deprecated MessageLoop methods in extensions.

extensions/browser/load_monitoring_extension_host_queue.cc

Index: extensions/browser/load_monitoring_extension_host_queue.cc
diff --git a/extensions/browser/load_monitoring_extension_host_queue.cc b/extensions/browser/load_monitoring_extension_host_queue.cc
index 0e9a9b1092edd6bd2dcc89c7400eb507062dbec5..429d35a959cf8f2f608e8a7cbc32d8bad0276591 100644
--- a/extensions/browser/load_monitoring_extension_host_queue.cc
+++ b/extensions/browser/load_monitoring_extension_host_queue.cc
@@ -8,9 +8,11 @@
 #include <utility>
 
 #include "base/bind.h"
+#include "base/location.h"
 #include "base/logging.h"
-#include "base/message_loop/message_loop.h"
 #include "base/metrics/histogram_macros.h"
+#include "base/single_thread_task_runner.h"
+#include "base/threading/thread_task_runner_handle.h"
 #include "content/public/browser/render_frame_host.h"
 #include "extensions/browser/extension_host.h"
 #include "extensions/browser/extension_host_observer.h"
@@ -46,7 +48,7 @@ void LoadMonitoringExtensionHostQueue::StartMonitoring() {
     return;
   }
   started_ = true;
-  base::MessageLoop::current()->PostDelayedTask(
+  base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
       FROM_HERE, base::Bind(&LoadMonitoringExtensionHostQueue::FinishMonitoring,
                             weak_ptr_factory_.GetWeakPtr()),
       monitor_time_);