Move FilePathWatcher class from browser/... to common/...

chrome/common/file_path_watcher/file_path_watcher.cc

+// Copyright (c) 2010 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.
+
+// Cross platform methods for FilePathWatcher. See the various platform
+// specific implementation files, too.
+
+#include "chrome/common/file_path_watcher/file_path_watcher.h"
+
+#include "base/logging.h"
+#include "base/message_loop.h"
+
+FilePathWatcher::~FilePathWatcher() {
+  impl_->Cancel();
+}
+
+bool FilePathWatcher::Watch(const FilePath& path,
+                            Delegate* delegate,
+                            scoped_refptr<base::MessageLoopProxy> loop) {
+  DCHECK(path.IsAbsolute());
+  impl_->set_message_loop(base::MessageLoopProxy::CreateForCurrentThread());

[Mattias Nissler (ping if slow), 2011/03/17 10:37:56]

This effectively allows you to instantiate a watcher on any thread, whereas
before it made sure that you can only run it on the FILE thread. Can we improve
this?

[dmac, 2011/03/17 17:16:48]

Down in the implementations we check to make sure that they are running on the
proper type of thread. Service process doesn't have the concept of browser
threads, so I'm not sure how we can enforce this any more than just checking the
type of the threads down in the implementation.

+  return impl_->Watch(path, delegate, loop);
+}
+
+FilePathWatcher::PlatformDelegate::~PlatformDelegate() {
+}
+
+void FilePathWatcher::PlatformDelegate::set_message_loop(
+    scoped_refptr<base::MessageLoopProxy> loop) {
+  CHECK(!message_loop_.get());
+  message_loop_ = loop;
+}
+
+void FilePathWatcher::DeletePlatformDelegate::Destruct(
+    const PlatformDelegate* delegate) {
+  scoped_refptr<base::MessageLoopProxy> loop = delegate->message_loop();
+  if (loop.get() == NULL || loop->BelongsToCurrentThread()) {
+    delete delegate;
+  } else {
+    loop->PostNonNestableTask(FROM_HERE,
+                              new DeleteTask<PlatformDelegate>(delegate));
+  }
+}