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

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

Index: third_party/WebKit/Source/modules/time_zone_monitor/TimeZoneMonitorClient.cpp
diff --git a/third_party/WebKit/Source/modules/time_zone_monitor/TimeZoneMonitorClient.cpp b/third_party/WebKit/Source/modules/time_zone_monitor/TimeZoneMonitorClient.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..78781408ca0625ab983b743afc3af5fca3b8dd5a
--- /dev/null
+++ b/third_party/WebKit/Source/modules/time_zone_monitor/TimeZoneMonitorClient.cpp
@@ -0,0 +1,77 @@
+// 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
+TimeZoneMonitorClient& TimeZoneMonitorClient::Init() {
+  DEFINE_STATIC_LOCAL(TimeZoneMonitorClient, instance, ());
+  return instance;
+}
+
+TimeZoneMonitorClient::TimeZoneMonitorClient() : m_binding(this) {
+  DCHECK(isMainThread());
+
+  device::mojom::blink::TimeZoneMonitorPtr monitor;
+  Platform::current()->interfaceProvider()->getInterface(
+      mojo::GetProxy(&monitor));
+  monitor->AddClient(m_binding.CreateInterfacePtrAndBind());
+}
+
+TimeZoneMonitorClient::~TimeZoneMonitorClient() {}
+
+void TimeZoneMonitorClient::OnTimeZoneChange(const WTF::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(

[blundell, 2016/10/18 12:32:11]

To be totally explicit about this issue:

This behavior is different from what it was previously, as now this task will be
posted to workerBackingThreads that don't own their platform thread. nhiroki's
comment upthread (and crbug.com/655028) seem to indicate that the *new* behavior
is the correct one, and that the old one was incorrect. nhiroki@, am I
understanding you correctly there?

If that is true, then this behavioral change should be called out in the CL
description.

I would also call out the changes that you're needing to make to support
initialization of Mojo in Blink now.

[leonhsl(Using Gerrit), 2016/10/18 14:34:48]

Acknowledged.

[nhiroki, 2016/10/19 02:13:47]

Yes, that's right.

[leonhsl(Using Gerrit), 2016/10/19 08:47:23]

Done. Updated cl description.

+                                          &NotifyTimezoneChangeOnWorkerThread));
+    posted.add(&thread->workerBackingThread());
+  }
+}
+
+}  // namespace blink