DIAL extension API skeleton.

chrome/browser/extensions/api/dial/dial_registry.cc

+// Copyright (c) 2012 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/extensions/api/dial/dial_registry.h"
+
+#include "chrome/browser/extensions/api/dial/dial_api.h"
+#include "chrome/browser/extensions/api/dial/dial_device_data.h"
+#include "chrome/common/extensions/api/dial.h"
+
+namespace extensions {
+
+DialRegistry::DialRegistry(Observer* dial_api)
+  : num_listeners_(0), discovering_(false), dial_api_(dial_api) { }
+
+DialRegistry::~DialRegistry() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+}
+
+void DialRegistry::OnListenerAdded() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  if (++num_listeners_ == 1) {
+    DVLOG(1) << "Listener added; starting periodic discovery.";
+    discovering_ = true;
+  }
+}
+
+void DialRegistry::OnListenerRemoved() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  if (--num_listeners_ == 0) {
+    DVLOG(1) << "Listeners removed; stopping periodic discovery.";
+    discovering_ = false;
+  }
+}
+
+bool DialRegistry::DiscoverNow() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  return discovering_;
+}
+
+}  // namespace extensions