[TimeZoneMonitor] Decouple //content/browser/time_zone_monitor* to //device/.

content/browser/time_zone_monitor.h

-// Copyright 2014 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.
-
-#ifndef CONTENT_BROWSER_TIME_ZONE_MONITOR_H_
-#define CONTENT_BROWSER_TIME_ZONE_MONITOR_H_
-
-#include <memory>
-
-#include "base/macros.h"
-#include "base/threading/thread_checker.h"
-#include "device/time_zone_monitor/public/interfaces/time_zone_monitor.mojom.h"
-#include "mojo/public/cpp/bindings/binding_set.h"
-#include "mojo/public/cpp/bindings/interface_ptr_set.h"
-
-template <class T>
-class scoped_refptr;
-
-namespace base {
-class SequencedTaskRunner;
-}
-
-namespace content {
-
-// TimeZoneMonitor watches the system time zone, and notifies renderers
-// when it changes. Some renderer code caches the system time zone, so
-// this notification is necessary to inform such code that cached
-// timezone data may have become invalid. Due to sandboxing, it is not
-// possible for renderer processes to monitor for system time zone
-// changes themselves, so this must happen in the browser process.
-//
-// Sandboxing also may prevent renderer processes from reading the time
-// zone when it does change, so platforms may have to deal with this in
-// platform-specific ways:
-//  - Mac uses a sandbox hole defined in content/renderer/renderer.sb.
-//  - Linux-based platforms use ProxyLocaltimeCallToBrowser in
-//    content/zygote/zygote_main_linux.cc and HandleLocaltime in
-//    content/browser/renderer_host/sandbox_ipc_linux.cc to override
-//    localtime in renderer processes with custom code that calls
-//    localtime in the browser process via Chrome IPC.
-
-class TimeZoneMonitor : public device::mojom::TimeZoneMonitor {
- public:
-  // Returns a new TimeZoneMonitor object (likely a subclass) specific to the
-  // platform. Inject |file_task_runner| to enable running blocking file
-  // operations on it when necessary.
-  static std::unique_ptr<TimeZoneMonitor> Create(
-      scoped_refptr<base::SequencedTaskRunner> file_task_runner);
-
-  ~TimeZoneMonitor() override;
-
-  void Bind(device::mojom::TimeZoneMonitorRequest request);
-
- protected:
-  TimeZoneMonitor();
-
-  // Notify all callbacks that the system time zone may have changed.
-  void NotifyClients();
-
- private:
-  base::ThreadChecker thread_checker_;
-
-  // device::mojom::device::mojom::TimeZoneMonitor:
-  void AddClient(device::mojom::TimeZoneMonitorClientPtr client) override;
-
-  mojo::BindingSet<device::mojom::TimeZoneMonitor> bindings_;
-  mojo::InterfacePtrSet<device::mojom::TimeZoneMonitorClient> clients_;
-  DISALLOW_COPY_AND_ASSIGN(TimeZoneMonitor);
-};
-
-}  // namespace content
-
-#endif  // CONTENT_BROWSER_TIME_ZONE_MONITOR_H_