Reduce usage of MessageLoopProxy in base/

base/files/file_path_watcher_win.cc

Index: base/files/file_path_watcher_win.cc
diff --git a/base/files/file_path_watcher_win.cc b/base/files/file_path_watcher_win.cc
index ec2fe6d22620c770340f9df3ca4976dfd550d427..1c557b1ada4e9a40f5ecadd9079ffc79464c5b35 100644
--- a/base/files/file_path_watcher_win.cc
+++ b/base/files/file_path_watcher_win.cc
@@ -11,6 +11,7 @@
 #include "base/logging.h"
 #include "base/memory/ref_counted.h"
 #include "base/message_loop/message_loop_proxy.h"
+#include "base/thread_task_runner_handle.h"
 #include "base/time/time.h"
 #include "base/win/object_watcher.h"
 
@@ -91,7 +92,7 @@ bool FilePathWatcherImpl::Watch(const FilePath& path,
                                 const FilePathWatcher::Callback& callback) {
   DCHECK(target_.value().empty());  // Can only watch one path.
 
-  set_message_loop(MessageLoopProxy::current());
+  set_task_runner(ThreadTaskRunnerHandle::Get());
   callback_ = callback;
   target_ = path;
   recursive_watch_ = recursive;
@@ -119,17 +120,17 @@ void FilePathWatcherImpl::Cancel() {
   }
 
   // Switch to the file thread if necessary so we can stop |watcher_|.
-  if (!message_loop()->BelongsToCurrentThread()) {
-    message_loop()->PostTask(FROM_HERE,
-                             Bind(&FilePathWatcher::CancelWatch,
-                                  make_scoped_refptr(this)));
+  if (!task_runner()->RunsTasksOnCurrentThread()) {
+    task_runner()->PostTask(
+        FROM_HERE,
+        Bind(&FilePathWatcher::CancelWatch, make_scoped_refptr(this)));
   } else {
     CancelOnMessageLoopThread();
   }
 }
 
 void FilePathWatcherImpl::CancelOnMessageLoopThread() {
-  DCHECK(message_loop()->BelongsToCurrentThread());
+  DCHECK(task_runner()->RunsTasksOnCurrentThread());
   set_cancelled();
 
   if (handle_ != INVALID_HANDLE_VALUE)