[Media Router] Create MediaSinkServiceBase and make DialMediaSinkService inherit from it

chrome/browser/media/router/discovery/dial/dial_media_sink_service.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_DIAL_DIAL_MEDIA_SINK_SERVICE_H_
-#define CHROME_BROWSER_MEDIA_ROUTER_DISCOVERY_DIAL_DIAL_MEDIA_SINK_SERVICE_H_
-
-#include <memory>
-#include <set>
-
-#include "chrome/browser/media/router/discovery/dial/device_description_service.h"
-#include "chrome/browser/media/router/discovery/dial/dial_registry.h"
-#include "chrome/common/media_router/discovery/media_sink_internal.h"
-#include "chrome/common/media_router/discovery/media_sink_service.h"
-
-namespace media_router {
-
-class DeviceDescriptionService;
-class DialRegistry;
-
-// A service which can be used to start background discovery and resolution of
-// DIAL devices (Smart TVs, Game Consoles, etc.).
-// This class is not thread safe. All methods must be called from the IO thread.
-class DialMediaSinkService : public MediaSinkService,
-                             public DialRegistry::Observer {
- public:
-  DialMediaSinkService(const OnSinksDiscoveredCallback& callback,
-                       net::URLRequestContextGetter* request_context);
-  ~DialMediaSinkService() override;
-
-  // Stops listening for DIAL device events.
-  virtual void Stop();
-
-  // MediaSinkService implementation
-  void Start() override;
-
- protected:
-
-  // Returns instance of device description service. Create a new one if none
-  // exists.
-  DeviceDescriptionService* GetDescriptionService();
-
-  // Does not take ownership of |dial_registry|.
-  void SetDialRegistryForTest(DialRegistry* dial_registry);
-  void SetDescriptionServiceForTest(
-      std::unique_ptr<DeviceDescriptionService> description_service);
-  void SetTimerForTest(std::unique_ptr<base::Timer> timer);
-
- private:
-  friend class DialMediaSinkServiceTest;
-  FRIEND_TEST_ALL_PREFIXES(DialMediaSinkServiceTest, TestStart);
-  FRIEND_TEST_ALL_PREFIXES(DialMediaSinkServiceTest, TestTimer);
-  FRIEND_TEST_ALL_PREFIXES(DialMediaSinkServiceTest,
-                           TestFetchCompleted_SameSink);
-  FRIEND_TEST_ALL_PREFIXES(DialMediaSinkServiceTest, TestIsDifferent);
-  FRIEND_TEST_ALL_PREFIXES(DialMediaSinkServiceTest,
-                           TestOnDeviceDescriptionAvailable);
-
-  // api::dial::DialRegistry::Observer implementation
-  void OnDialDeviceEvent(const DialRegistry::DeviceList& devices) override;
-  void OnDialError(DialRegistry::DialErrorCode type) override;
-
-  // Called when description service successfully fetches and parses device
-  // description XML. Restart |finish_timer_| if it is not running.
-  void OnDeviceDescriptionAvailable(
-      const DialDeviceData& device_data,
-      const ParsedDialDeviceDescription& description_data);
-
-  // Called when fails to fetch or parse device description XML.
-  void OnDeviceDescriptionError(const DialDeviceData& device,
-                                const std::string& error_message);
-
-  // Called when |finish_timer_| expires.
-  void OnFetchCompleted();
-
-  // Helper function to start |finish_timer_|.
-  void StartTimer();
-
-  // Timer for finishing fetching. Starts in |OnDialDeviceEvent()|, and expires
-  // 3 seconds later. If |OnDeviceDescriptionAvailable()| is called after
-  // |finish_timer_| expires, |finish_timer_| is restarted.
-  std::unique_ptr<base::Timer> finish_timer_;
-
-  std::unique_ptr<DeviceDescriptionService> description_service_;
-
-  // Raw pointer to DialRegistry singleton.
-  DialRegistry* dial_registry_ = nullptr;
-
-  // Sorted sinks from current round of discovery.
-  std::set<MediaSinkInternal> current_sinks_;
-
-  // Sorted sinks sent to Media Router Provider in last FetchCompleted().
-  std::set<MediaSinkInternal> mrp_sinks_;
-
-  // Device data list from current round of discovery.
-  DialRegistry::DeviceList current_devices_;
-
-  scoped_refptr<net::URLRequestContextGetter> request_context_;
-};
-
-}  // namespace media_router
-
-#endif  // CHROME_BROWSER_MEDIA_ROUTER_DISCOVERY_DIAL_DIAL_MEDIA_SINK_SERVICE_H_