Mojoify time zone update IPC from browser to renderer

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 "device/time/public/interfaces/time_zone_monitor.mojom.h"
+#include "mojo/public/cpp/bindings/binding_set.h"
 
 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 {
+// TODO(blundell): Update this class to be named TimeZoneMonitorImpl.

[jam, 2016/09/06 22:11:18]

nit: btw no need to do that. the reason interfaces are in the "mojom"
subnamespace is that the impls don't need to end in Impl (that's the reason
given for that mojom intermediate namespace)

[blundell, 2016/09/07 14:40:05]

Ah convenient.

+class TimeZoneMonitor : public device::mojom::TimeZoneMonitor {
  public:
   // Returns a new TimeZoneMonitor object (likely a subclass) specific to the
   // platform.
   static std::unique_ptr<TimeZoneMonitor> Create();
 
-  virtual ~TimeZoneMonitor();
+  ~TimeZoneMonitor() override;
+
+  void Bind(device::mojom::TimeZoneMonitorRequest request);
 
  protected:
   TimeZoneMonitor();
 
-  // Loop over all renderers and notify them that the system time zone may
-  // have changed.
-  void NotifyRenderers();
+  // Notify all callbacks that the system time zone may have changed.
+  void NotifyClients();
 
  private:
+  // device::mojom::device::mojom::TimeZoneMonitor:
+  void QueryNextTimeZoneChange(
+      const device::mojom::TimeZoneMonitor::QueryNextTimeZoneChangeCallback&
+          callback) override;
+
+  mojo::BindingSet<device::mojom::TimeZoneMonitor> bindings_;
+  std::vector<device::mojom::TimeZoneMonitor::QueryNextTimeZoneChangeCallback>
+      on_time_zone_change_tasks_;
   DISALLOW_COPY_AND_ASSIGN(TimeZoneMonitor);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_TIME_ZONE_MONITOR_H_