Remove use of deprecated MessageLoop methods in extensions.

extensions/browser/api/cast_channel/cast_socket_unittest.cc

Index: extensions/browser/api/cast_channel/cast_socket_unittest.cc
diff --git a/extensions/browser/api/cast_channel/cast_socket_unittest.cc b/extensions/browser/api/cast_channel/cast_socket_unittest.cc
index 4db753a17755b65dfde494e485360b0e7572099f..c97af97b34e596739d10e5e0c86c8172835f9560 100644
--- a/extensions/browser/api/cast_channel/cast_socket_unittest.cc
+++ b/extensions/browser/api/cast_channel/cast_socket_unittest.cc
@@ -9,14 +9,17 @@
 #include <utility>
 #include <vector>
 
+#include "base/location.h"
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/memory/weak_ptr.h"
 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
+#include "base/single_thread_task_runner.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/sys_byteorder.h"
 #include "base/test/simple_test_clock.h"
+#include "base/threading/thread_task_runner_handle.h"
 #include "base/timer/mock_timer.h"
 #include "extensions/browser/api/cast_channel/cast_auth_util.h"
 #include "extensions/browser/api/cast_channel/cast_framer.h"
@@ -108,9 +111,8 @@ class MockTCPSocket : public net::TCPClientSocket {
 
     if (connect_data_.mode == net::ASYNC) {
       CHECK_NE(connect_data_.result, net::ERR_IO_PENDING);
-      base::MessageLoop::current()->PostTask(
-          FROM_HERE,
-          base::Bind(callback, connect_data_.result));
+      base::ThreadTaskRunnerHandle::Get()->PostTask(
+          FROM_HERE, base::Bind(callback, connect_data_.result));
       return net::ERR_IO_PENDING;
     } else {
       return connect_data_.result;