[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, ());
+
+  device::mojom::blink::TimeZoneMonitorPtr monitor;
+  Platform::current()->interfaceProvider()->getInterface(
+      mojo::GetProxy(&monitor));
+  monitor->AddClient(instance.m_binding.CreateInterfacePtrAndBind());

[dcheng, 2016/10/31 23:45:35]

Nit: Personal preference here, but I prefer that we do all the initialization in
the ctor, by something like this:

device::mojom::blink::TimeZoneMonitorClientPtr clientPtr;
DEFINE_STATIC_LOCAL(TimeZoneMonitorClient, instance, (&clientPtr));

Since I'm not a fan of the constructor leaving an object partially initialized
if it's not necessary.

+}
+
+TimeZoneMonitorClient::TimeZoneMonitorClient() : m_binding(this) {
+  DCHECK(isMainThread());
+}
+
+TimeZoneMonitorClient::~TimeZoneMonitorClient() {}
+
+void TimeZoneMonitorClient::OnTimeZoneChange(const String& timeZoneInfo) {
+  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