Revert of base: Remove use of MessageLoopProxy

base/files/file_path_watcher_linux.cc

Index: base/files/file_path_watcher_linux.cc
diff --git a/base/files/file_path_watcher_linux.cc b/base/files/file_path_watcher_linux.cc
index ba2f1d96c84c40955a3fac8ab8ffbd7f7642ab04..06c517ae7dfba43342de7b888bd1b8790367b87e 100644
--- a/base/files/file_path_watcher_linux.cc
+++ b/base/files/file_path_watcher_linux.cc
@@ -26,10 +26,10 @@
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/message_loop/message_loop.h"
+#include "base/message_loop/message_loop_proxy.h"
 #include "base/posix/eintr_wrapper.h"
-#include "base/single_thread_task_runner.h"
 #include "base/synchronization/lock.h"
-#include "base/thread_task_runner_handle.h"
 #include "base/threading/thread.h"
 #include "base/trace_event/trace_event.h"
 
@@ -264,7 +264,7 @@
   shutdown_pipe_[0] = -1;
   shutdown_pipe_[1] = -1;
   if (inotify_fd_ >= 0 && pipe(shutdown_pipe_) == 0 && thread_.Start()) {
-    thread_.task_runner()->PostTask(
+    thread_.message_loop()->PostTask(
         FROM_HERE,
         Bind(&InotifyReaderCallback, this, inotify_fd_, shutdown_pipe_[0]));
     valid_ = true;
@@ -349,11 +349,12 @@
                                             bool created,
                                             bool deleted,
                                             bool is_dir) {
-  if (!task_runner()->BelongsToCurrentThread()) {
-    // Switch to task_runner() to access |watches_| safely.
-    task_runner()->PostTask(FROM_HERE,
-                            Bind(&FilePathWatcherImpl::OnFilePathChanged, this,
-                                 fired_watch, child, created, deleted, is_dir));
+  if (!message_loop()->BelongsToCurrentThread()) {
+    // Switch to message_loop() to access |watches_| safely.
+    message_loop()->PostTask(
+        FROM_HERE,
+        Bind(&FilePathWatcherImpl::OnFilePathChanged, this,
+             fired_watch, child, created, deleted, is_dir));
     return;
   }
 
@@ -451,7 +452,7 @@
   DCHECK(target_.empty());
   DCHECK(MessageLoopForIO::current());
 
-  set_task_runner(ThreadTaskRunnerHandle::Get());
+  set_message_loop(MessageLoopProxy::current());
   callback_ = callback;
   target_ = path;
   recursive_ = recursive;
@@ -475,16 +476,17 @@
   }
 
   // Switch to the message_loop() if necessary so we can access |watches_|.
-  if (!task_runner()->BelongsToCurrentThread()) {
-    task_runner()->PostTask(FROM_HERE, Bind(&FilePathWatcher::CancelWatch,
-                                            make_scoped_refptr(this)));
+  if (!message_loop()->BelongsToCurrentThread()) {
+    message_loop()->PostTask(FROM_HERE,
+                             Bind(&FilePathWatcher::CancelWatch,
+                                  make_scoped_refptr(this)));
   } else {
     CancelOnMessageLoopThread();
   }
 }
 
 void FilePathWatcherImpl::CancelOnMessageLoopThread() {
-  DCHECK(task_runner()->BelongsToCurrentThread());
+  DCHECK(message_loop()->BelongsToCurrentThread());
   set_cancelled();
 
   if (!callback_.is_null()) {
@@ -508,7 +510,7 @@
 void FilePathWatcherImpl::UpdateWatches() {
   // Ensure this runs on the message_loop() exclusively in order to avoid
   // concurrency issues.
-  DCHECK(task_runner()->BelongsToCurrentThread());
+  DCHECK(message_loop()->BelongsToCurrentThread());
   DCHECK(HasValidWatchVector());
 
   // Walk the list of watches and update them as we go.