Add the basic code skeleton for system info event router

chrome/browser/extensions/system_info_watcher_mac.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/extensions/system_info_watcher.h"
+
+namespace extensions {
+
+// TODO(Hongbo): Add SystemInfoWatcher implementation on Mac platform.
+class SystemInfoWatcherMac : public SystemInfoWatcher {
+ public:
+  SystemInfoWatcherMac();
+  virtual ~SystemInfoWatcherMac();
+
+ private:
+  virtual bool PlatformStartWatching(const std::string& event_name) OVERRIDE;
+  virtual bool PlatformStopWatching(const std::string& event_name) OVERRIDE;
+};
+
+//
+// SystemInfoWatcherMac implementation.
+//
+
+SystemInfoWatcherMac::SystemInfoWatcherMac() {
+}
+
+SystemInfoWatcherMac::~SystemInfoWatcherMac() {
+}
+
+bool SystemInfoWatcherMac::PlatformStartWatching(
+    const std::string& event_name) {
+  return false;
+}
+
+bool SystemInfoWatcherMac::PlatformStopWatching(
+    const std::string& event_name) {
+  return false;
+}
+
+// static
+SystemInfoWatcher* SystemInfoWatcher::Get() {
+  return SystemInfoWatcher::GetInstance<SystemInfoWatcherMac>();
+}
+
+}  // namespace extensions