Listen for changes to the system time zone, and broadcast a NotifyTimezoneChange to all RenderViewHo

chrome/browser/mac/timezone_notification.mm

+// Copyright 2014 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 "chrome/browser/mac/timezone_notification.h"
+
+#include <CoreFoundation/CoreFoundation.h>
+#import <Foundation/Foundation.h>
+
+#include "base/compiler_specific.h"
+#include "base/logging.h"
+#include "base/memory/scoped_ptr.h"
+#include "content/public/browser/render_view_host.h"
+#include "content/public/browser/render_widget_host.h"
+#include "content/public/browser/render_widget_host_iterator.h"
+
+namespace {
+
+void NotifyRenderers() {
+  scoped_ptr<content::RenderWidgetHostIterator> widgets(
+      content::RenderWidgetHost::GetRenderWidgetHosts());
+  while (content::RenderWidgetHost* widget = widgets->GetNextHost()) {
+    if (widget->IsRenderView()) {
+      content::RenderViewHost* view = content::RenderViewHost::From(widget);
+      view->NotifyTimezoneChange();
+    }
+  }
+}
+
+}  // namespace
+
+@interface TimeZoneWatcher : NSObject
+- (void)systemTimeZoneDidChange:(NSNotification*)notification;
+@end
+
+@implementation TimeZoneWatcher
+
+- (id)init {
+  if ((self = [super init])) {
+    NSNotificationCenter* nc = [NSNotificationCenter defaultCenter];
+    [nc addObserver:self
+           selector:@selector(systemTimeZoneDidChange:)
+               name:NSSystemTimeZoneDidChangeNotification
+             object:nil];
+  }
+  return self;
+}
+
+- (void)dealloc {
+  [[NSNotificationCenter defaultCenter] removeObserver:self];
+  return [super dealloc];
+}
+
+- (void)systemTimeZoneDidChange:(NSNotification*)notification {
+  NotifyRenderers();
+}
+
+void ListenForTimeZoneChanges() {
+  DCHECK_EQ(CFRunLoopGetCurrent(), CFRunLoopGetMain());
+  static TimeZoneWatcher* tzw ALLOW_UNUSED = [[TimeZoneWatcher alloc] init];
+}
+
+@end