gdata: Move task related functions like RunTaskOnUIThread from gdata_file_system.cc to task_util.cc

chrome/browser/chromeos/gdata/task_util.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 "chrome/browser/chromeos/gdata/task_util.h"
+
+#include "base/location.h"
+#include "content/public/browser/browser_thread.h"
+
+using content::BrowserThread;
+
+namespace gdata {
+
+void RunTaskOnThread(scoped_refptr<base::MessageLoopProxy> relay_proxy,
+                     const base::Closure& task) {
+  if (relay_proxy->BelongsToCurrentThread()) {
+    task.Run();
+  } else {
+    const bool posted = relay_proxy->PostTask(FROM_HERE, task);
+    DCHECK(posted);
+  }
+}
+
+void RunTaskOnUIThread(const base::Closure& task) {
+  RunTaskOnThread(
+      BrowserThread::GetMessageLoopProxyForThread(BrowserThread::UI), task);
+}
+
+}  // namespace gdata