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

content/common/file_path_watcher/file_path_watcher.cc

+// Copyright (c) 2011 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 "content/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,
+                            base::MessageLoopProxy* loop) {
+  DCHECK(path.IsAbsolute());
+  return impl_->Watch(path, delegate, loop);
+}
+
+FilePathWatcher::PlatformDelegate::PlatformDelegate() {
+}
+
+FilePathWatcher::PlatformDelegate::~PlatformDelegate() {
+}
+
+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));
+  }
+}