Mojoify time zone update IPC from browser to renderer

device/time/public/interfaces/time_zone_monitor.mojom

Index: device/time/public/interfaces/time_zone_monitor.mojom
diff --git a/device/sensors/public/interfaces/light.mojom b/device/time/public/interfaces/time_zone_monitor.mojom
similarity index 56%
copy from device/sensors/public/interfaces/light.mojom
copy to device/time/public/interfaces/time_zone_monitor.mojom
index 3c12347dd39f2a6f3ecff27f4e5ba494de2ddd48..e1ac22f28fc71280460901d5c9821e7f7147ceae 100644
--- a/device/sensors/public/interfaces/light.mojom
+++ b/device/time/public/interfaces/time_zone_monitor.mojom
@@ -4,7 +4,7 @@
 
 module device.mojom;
 
-interface LightSensor {
-  StartPolling() => (handle<shared_buffer> memory_handle);
-  StopPolling();
+interface TimeZoneMonitor {

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

if we don't forsee any other methods in this interface for generic "time"
service, then the code should live in device/time_zone_monitor to make the
directory name clearer

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

I think that sooner or later we'll need the POSIX-specific method to get
localtime() (as we discussed in the design doc). I'm not sure when I'll get to
that though, so I'm happy to rename to what makes sense now and it's easy enough
to change later if/when appropriate.

+  // Time zone changes are reported along with the new time zone ID.
+  QueryNextTimeZoneChange() => (string tz_info);
 };