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..f414e979ab9c422ee4554789325a34635e8aa9d9 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 +22,33 @@ 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();
+#if defined(OS_LINUX)
+  // We get here multiple times on Linux per a single tz change, but
+  // want to update the ICU default zone and notify renderer only once.
+  scoped_ptr<icu::TimeZone> current_zone(icu::TimeZone::createDefault());
+  if (*current_zone == *new_zone) {
+    VLOG(1) << "timezone already updated";
+    delete new_zone;
+    return;
+  }
+#endif
+  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(1) << "timezone reset to " << zone_id_str;
   for (RenderProcessHost::iterator iterator =
            RenderProcessHost::AllHostsIterator();
        !iterator.IsAtEnd();
        iterator.Advance()) {
-    iterator.GetCurrentValue()->NotifyTimezoneChange();
+    iterator.GetCurrentValue()->NotifyTimezoneChange(zone_id_str);
   }
 }