[mDns] Make DnsSdRegistry a leaky singleton

chrome/browser/media/router/discovery/mdns/mock_dns_sd_registry.h

+// Copyright 2017 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.
+
+#ifndef CHROME_BROWSER_MEDIA_ROUTER_DISCOVERY_MDNS_MOCK_DNS_SD_REGISTRY_H_
+#define CHROME_BROWSER_MEDIA_ROUTER_DISCOVERY_MDNS_MOCK_DNS_SD_REGISTRY_H_
+
+#include "chrome/browser/media/router/discovery/mdns/dns_sd_registry.h"
+#include "testing/gmock/include/gmock/gmock.h"
+
+namespace media_router {
+
+class MockDnsSdRegistry : public DnsSdRegistry {
+ public:
+  explicit MockDnsSdRegistry(DnsSdObserver* observer);
+  ~MockDnsSdRegistry() override;
+
+  MOCK_METHOD1(AddObserver, void(DnsSdObserver* observer));
+  MOCK_METHOD1(RemoveObserver, void(DnsSdObserver* observer));
+  MOCK_METHOD1(RegisterDnsSdListener, void(const std::string& service_type));
+  MOCK_METHOD1(UnregisterDnsSdListener, void(const std::string& service_type));
+  MOCK_METHOD1(Publish, void(const std::string&));
+  MOCK_METHOD0(ForceDiscovery, void(void));
+
+  void DispatchMDnsEvent(const std::string& service_type,
+                         const DnsSdServiceList& services);
+
+ private:
+  DnsSdObserver* observer_;
+};
+
+}  // namespace media_router
+
+#endif  // CHROME_BROWSER_MEDIA_ROUTER_DISCOVERY_MDNS_MOCK_DNS_SD_REGISTRY_H_