[Media Router] Add DialMediaSinkService and DeviceDescriptionService

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 content {
+class BrowserContext;
+}
+
+namespace media_router {
+
+class DeviceDescriptionService;
+class DialRegistry;
+
+class DialMediaSinkService : public MediaSinkService,

[imcheng, 2017/04/26 22:52:16]

Could you please backfill class comments here?

[zhaobin, 2017/04/27 01:41:20]

Done.

+                             public DialRegistry::Observer {
+ public:
+  DialMediaSinkService(const OnSinksDiscoveredCallback& callback,
+                       content::BrowserContext* browser_context,
+                       net::URLRequestContextGetter* request_context);
+  ~DialMediaSinkService() override;
+
+  // MediaSinkService implementation
+  void Start() override;
+  void AddSinkQuery(MediaSinksObserver* observer) override;
+  void RemoveSinkQuery(MediaSinksObserver* observer) override;
+
+  void Stop();
+
+ protected:
+  virtual DialRegistry* dial_registry();
+
+  // Returns instance of device description service. Create a new one if none
+  // exists.
+  virtual DeviceDescriptionService* GetDescriptionService();
+
+ private:
+  friend class DialMediaSinkServiceTest;
+  FRIEND_TEST_ALL_PREFIXES(DialMediaSinkServiceTest, TestStart);
+  FRIEND_TEST_ALL_PREFIXES(DialMediaSinkServiceTest, TestFetchCompleted);
+  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.
+  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();
+
+  // Timer for finishing fetching for the first time (returns some devices to
+  // user ASAP).
+  std::unique_ptr<base::OneShotTimer> finish_timer_;
+
+  std::unique_ptr<DeviceDescriptionService> description_service_;
+
+  // 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_;
+
+  content::BrowserContext* browser_context_;
+  scoped_refptr<net::URLRequestContextGetter> request_context_;
+};
+
+}  // namespace media_router
+
+#endif  // CHROME_BROWSER_MEDIA_ROUTER_DISCOVERY_DIAL_DIAL_MEDIA_SINK_SERVICE_H_