[TimeZoneMonitor] Decouple renderer side impl from content to blink.

third_party/WebKit/Source/modules/time_zone_monitor/TimeZoneMonitorClient.cpp

+// Copyright 2016 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.
+
+#include "modules/time_zone_monitor/TimeZoneMonitorClient.h"
+
+#include "bindings/core/v8/V8Binding.h"
+#include "bindings/core/v8/V8PerIsolateData.h"
+#include "core/dom/ExecutionContext.h"
+#include "core/dom/ExecutionContextTask.h"
+#include "core/workers/WorkerBackingThread.h"
+#include "core/workers/WorkerThread.h"
+#include "public/platform/InterfaceProvider.h"
+#include "public/platform/Platform.h"
+#include "third_party/icu/source/i18n/unicode/timezone.h"
+#include <v8.h>
+
+namespace blink {
+
+namespace {
+
+// Notify V8 that the date/time configuration of the system might have changed.
+void NotifyTimezoneChangeToV8(v8::Isolate* isolate) {
+  DCHECK(isolate);
+  v8::Date::DateTimeConfigurationChangeNotification(isolate);
+}
+
+void NotifyTimezoneChangeOnWorkerThread(ExecutionContext* context) {
+  NotifyTimezoneChangeToV8(toIsolate(context));
+}
+
+}  // namespace
+
+// static
+void TimeZoneMonitorClient::Init() {
+  DEFINE_STATIC_LOCAL(TimeZoneMonitorClient, instance, ());
+  instance.Bind();
+}
+
+TimeZoneMonitorClient::TimeZoneMonitorClient() : m_binding(this) {
+  DCHECK(isMainThread());
+}
+
+TimeZoneMonitorClient::~TimeZoneMonitorClient() {}
+
+void TimeZoneMonitorClient::Bind() {
+  DCHECK(isMainThread());
+  if (m_binding.is_bound())

[blundell, 2016/10/27 15:31:19]

Do you expect this method to be called more than once?

[leonhsl(Using Gerrit), 2016/10/28 05:59:06]

This should happen only once, so I added the guard, maybe should change to use
DCHECK?
Actually I created TimeZoneMonitorClient::Bind() function because I must USE the
'instance' created by DEFINE_STATIC_LOCAL at line36 in
TimeZoneMonitorClient::Init(), otherwise compiler will warn(error) 'unused
variable' there.. Seems weird,, but I have no other good ideas to handle this
well. Any suggestion?

[blundell, 2016/10/28 14:36:13]

You could presumably just inline the code and use instance.m_binding instead of
m_binding?

[leonhsl(Using Gerrit), 2016/10/30 13:24:18]

Done.

+    return;
+
+  device::mojom::blink::TimeZoneMonitorPtr monitor;
+  Platform::current()->interfaceProvider()->getInterface(
+      mojo::GetProxy(&monitor));
+  monitor->AddClient(m_binding.CreateInterfacePtrAndBind());
+}
+
+void TimeZoneMonitorClient::OnTimeZoneChange(const WTF::String& timeZoneInfo) {

[dcheng, 2016/10/27 22:34:50]

Nit: omit WTF::

[leonhsl(Using Gerrit), 2016/10/28 05:59:06]

Done.

+  DCHECK(isMainThread());
+
+  if (!timeZoneInfo.isEmpty()) {
+    icu::TimeZone* zone = icu::TimeZone::createTimeZone(
+        icu::UnicodeString::fromUTF8(timeZoneInfo.utf8().data()));
+    icu::TimeZone::adoptDefault(zone);
+    VLOG(1) << "ICU default timezone is set to " << timeZoneInfo;
+  }
+
+  NotifyTimezoneChangeToV8(V8PerIsolateData::mainThreadIsolate());
+
+  HashSet<WorkerThread*>& threads = WorkerThread::workerThreads();
+  HashSet<WorkerBackingThread*> posted;
+  for (WorkerThread* thread : threads) {
+    // Ensure every WorkerBackingThread(holding one platform thread) only get
+    // the task posted once, because one WorkerBackingThread could be shared
+    // among multiple WorkerThreads.
+    if (posted.contains(&thread->workerBackingThread()))
+      continue;
+    thread->postTask(BLINK_FROM_HERE, createCrossThreadTask(
+                                          &NotifyTimezoneChangeOnWorkerThread));
+    posted.add(&thread->workerBackingThread());
+  }
+}
+
+}  // namespace blink