Use FileDescriptorWatcher in ProcessOutputWatcher

chromeos/process_proxy/process_output_watcher.cc

 // Copyright (c) 2012 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 "chromeos/process_proxy/process_output_watcher.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 49 matching lines @@
   // We want to be sure we will be able to add 0 at the end of the input, so -1.
   read_buffer_capacity_ = arraysize(read_buffer_) - 1;
 }
 
 ProcessOutputWatcher::~ProcessOutputWatcher() {}
 
 void ProcessOutputWatcher::Start() {
   WatchProcessOutput();
 }
 
-void ProcessOutputWatcher::OnFileCanReadWithoutBlocking(int fd) {
-  DCHECK_EQ(process_output_file_.GetPlatformFile(), fd);
-
-  output_file_watcher_.StopWatchingFileDescriptor();
-  ReadFromFd(fd);
-}
-
-void ProcessOutputWatcher::OnFileCanWriteWithoutBlocking(int fd) {
-  NOTREACHED();
+void ProcessOutputWatcher::OnProcessOutputCanReadWithoutBlocking() {
+  output_file_watcher_.reset();
+  ReadFromFd(process_output_file_.GetPlatformFile());
 }
 
 void ProcessOutputWatcher::WatchProcessOutput() {
-  base::MessageLoopForIO::current()->WatchFileDescriptor(
-      process_output_file_.GetPlatformFile(), false,
-      base::MessageLoopForIO::WATCH_READ, &output_file_watcher_, this);
+  output_file_watcher_ = base::FileDescriptorWatcher::WatchReadable(
+      process_output_file_.GetPlatformFile(),
+      base::Bind(&ProcessOutputWatcher::OnProcessOutputCanReadWithoutBlocking,
+                 base::Unretained(this)));
 }
 
 void ProcessOutputWatcher::ReadFromFd(int fd) {
   // We don't want to necessary read pipe until it is empty so we don't starve
   // other streams in case data is written faster than we read it. If there is
   // more than read_buffer_size_ bytes in pipe, it will be read in the next
   // iteration.
   DCHECK_GT(read_buffer_capacity_, read_buffer_size_);
   ssize_t bytes_read =
       HANDLE_EINTR(read(fd, &read_buffer_[read_buffer_size_],
@@ skipping 68 matching lines @@
   // update the buffer size accordingly.
   if (output_to_report < read_buffer_size_) {
     for (size_t i = output_to_report; i < read_buffer_size_; ++i) {
       read_buffer_[i - output_to_report] = read_buffer_[i];
     }
   }
   read_buffer_size_ -= output_to_report;
 }
 
 }  // namespace chromeos