Stop checking that FilePathWatcher is used from a MessageLoopForIO.

base/files/file_path_watcher_fsevents.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/files/file_path_watcher_fsevents.h"
 
 #include <dispatch/dispatch.h>
 
 #include <list>
 
 #include "base/bind.h"
 #include "base/files/file_util.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/mac/scoped_cftyperef.h"
 #include "base/macros.h"
-#include "base/message_loop/message_loop.h"
 #include "base/strings/stringprintf.h"
 #include "base/threading/thread_task_runner_handle.h"
 
 namespace base {
 
 namespace {
 
 // The latency parameter passed to FSEventsStreamCreate().
 const CFAbsoluteTime kEventLatencySeconds = 0.3;
 
@@ skipping 44 matching lines @@
     : queue_(dispatch_queue_create(
           base::StringPrintf(
               "org.chromium.base.FilePathWatcher.%p", this).c_str(),
           DISPATCH_QUEUE_SERIAL)),
       fsevent_stream_(nullptr) {
 }
 
 bool FilePathWatcherFSEvents::Watch(const FilePath& path,
                                     bool recursive,
                                     const FilePathWatcher::Callback& callback) {
-  DCHECK(MessageLoopForIO::current());
   DCHECK(!callback.is_null());
   DCHECK(callback_.is_null());
 
   // This class could support non-recursive watches, but that is currently
   // left to FilePathWatcherKQueue.
   if (!recursive)
     return false;
 
   set_task_runner(ThreadTaskRunnerHandle::Get());
   callback_ = callback;
@@ skipping 174 matching lines @@
 void FilePathWatcherFSEvents::StartEventStream(FSEventStreamEventId start_event,
                                                const FilePath& path) {
   DCHECK(resolved_target_.empty());
 
   target_ = path;
   ResolveTargetPath();
   UpdateEventStream(start_event);
 }
 
 }  // namespace base