Revert of base: Remove use of MessageLoopProxy

base/files/file_util_proxy_unittest.cc

Index: base/files/file_util_proxy_unittest.cc
diff --git a/base/files/file_util_proxy_unittest.cc b/base/files/file_util_proxy_unittest.cc
index 74083699f00f8ff2b0ed14698c9f4beb602c240f..5eb68193687234b6a302fa8fd23718e0e784dd15 100644
--- a/base/files/file_util_proxy_unittest.cc
+++ b/base/files/file_util_proxy_unittest.cc
@@ -8,6 +8,7 @@
 #include "base/files/file_util.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/memory/weak_ptr.h"
+#include "base/message_loop/message_loop.h"
 #include "base/threading/thread.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ -39,7 +40,7 @@
 
  protected:
   TaskRunner* file_task_runner() const {
-    return file_thread_.task_runner().get();
+    return file_thread_.message_loop_proxy().get();
   }
   const FilePath& test_dir_path() const { return dir_.path(); }
   const FilePath test_path() const { return dir_.path().AppendASCII("test"); }