Update the ICU's default timezone in render

content/browser/time_zone_monitor.cc

Index: content/browser/time_zone_monitor.cc
diff --git a/content/browser/time_zone_monitor.cc b/content/browser/time_zone_monitor.cc
index f61280b23a193ec0da98f0c46bc687b77abd6461..9831f74ef80b0cf30250a1556e021d07149ef47f 100644
--- a/content/browser/time_zone_monitor.cc
+++ b/content/browser/time_zone_monitor.cc
@@ -7,6 +7,8 @@
 #include "base/logging.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/render_process_host.h"
+#include "third_party/icu/source/common/unicode/unistr.h"
+#include "third_party/icu/source/i18n/unicode/timezone.h"
 
 namespace content {
 
@@ -20,11 +22,23 @@ TimeZoneMonitor::~TimeZoneMonitor() {
 
 void TimeZoneMonitor::NotifyRenderers() {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
+#if defined(OS_CHROMEOS)
+  // On CrOS, ICU's default tz is already set to a new zone. No
+  // need to redetect it with detectHostTimeZone().
+  scoped_ptr<icu::TimeZone> new_zone(icu::TimeZone::createDefault());
+#else
+  icu::TimeZone* new_zone = icu::TimeZone::detectHostTimeZone();
+  icu::TimeZone::adoptDefault(new_zone);
+#endif
+  icu::UnicodeString zone_id;
+  std::string zone_id_str;
+  new_zone->getID(zone_id).toUTF8String(zone_id_str);
+  VLOG(0) << "timezone reset to " << zone_id_str;

[jungshik at Google, 2015/04/10 00:23:44]

I expected this function to be called only once per tz change, but I got this
log msg 3 times for each tz change I made on Linux. I wonder why. 

BTW, I'll increase the verbosity level. 

[Mark Mentovai, 2015/04/10 13:18:59]

Jungshik at google wrote:
Linux doesn’t have a standard way to notify of system time zone changes, so we
watch three files in /etc that should cover the majority of cases. Some systems
have more than one of those files (the one here has two of them), so they get
more than one notification. See content/browser/time_zone_monitor_linux.cc.

   for (RenderProcessHost::iterator iterator =
            RenderProcessHost::AllHostsIterator();
        !iterator.IsAtEnd();
        iterator.Advance()) {
-    iterator.GetCurrentValue()->NotifyTimezoneChange();
+    iterator.GetCurrentValue()->NotifyTimezoneChange(zone_id_str);
   }
 }