[Media Router] Add MediaSink subtypes

chrome/browser/media/router/media_sink_internal.cc

+// 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.
+
+#include "chrome/browser/media/router/media_sink_internal.h"
+
+#include "base/logging.h"
+
+namespace media_router {
+
+MediaSinkInternal::MediaSinkInternal(const MediaSink& sink)
+    : sink_(sink), type_(SinkType::GENERIC) {}
+
+MediaSinkInternal::MediaSinkInternal(const MediaSink& sink,
+                                     const DialSinkExtraData& dial_data)
+    : sink_(sink), type_(SinkType::DIAL), dial_data_(dial_data) {}
+
+MediaSinkInternal::MediaSinkInternal(const MediaSink& sink,
+                                     const CastSinkExtraData& cast_data)
+    : sink_(sink), type_(SinkType::CAST), cast_data_(cast_data) {}
+
+MediaSinkInternal::MediaSinkInternal() : type_(SinkType::GENERIC) {}
+
+MediaSinkInternal::MediaSinkInternal(const MediaSinkInternal& other) = default;
+
+MediaSinkInternal::~MediaSinkInternal() = default;
+
+void MediaSinkInternal::set_sink(const MediaSink& sink) {
+  type_ = SinkType::GENERIC;

[imcheng, 2017/02/24 23:54:20]

Hmm... so set_sink changes the type but not the extra data fields?
I think it would also work if we made sure |type_| is currently GENERIC when
calling set_{dial,cast}_data instead.

[zhaobin, 2017/02/27 21:45:14]

Done.

+  sink_ = sink;
+}
+
+void MediaSinkInternal::set_dial_data(const DialSinkExtraData& dial_data) {

[mark a. foltz, 2017/02/25 01:10:23]

I don't think you should be able to change the type of a sink from CAST to DIAL
or vice versa.
Can you DCHECK(dial_data_ || !cast_data_)?

[zhaobin, 2017/02/27 21:45:14]

Done.

+  type_ = SinkType::DIAL;
+  dial_data_ = dial_data;
+}
+
+const DialSinkExtraData& MediaSinkInternal::dial_data() const {
+  DCHECK(is_dial_sink());
+  DCHECK(dial_data_.has_value());

[mark a. foltz, 2017/02/25 01:10:23]

This DCHECK is redundant with the one in Optional.

[zhaobin, 2017/02/27 21:45:14]

Done.

+  return *dial_data_;
+}
+
+void MediaSinkInternal::set_cast_data(const CastSinkExtraData& cast_data) {
+  type_ = SinkType::CAST;
+  cast_data_ = cast_data;
+}
+
+const CastSinkExtraData& MediaSinkInternal::cast_data() const {
+  DCHECK(is_cast_sink());
+  DCHECK(cast_data_.has_value());
+  return *cast_data_;
+}
+
+DialSinkExtraData::DialSinkExtraData() = default;
+DialSinkExtraData::DialSinkExtraData(const DialSinkExtraData& other) = default;
+DialSinkExtraData::~DialSinkExtraData() = default;
+
+CastSinkExtraData::CastSinkExtraData() = default;
+CastSinkExtraData::CastSinkExtraData(const CastSinkExtraData& other) = default;
+CastSinkExtraData::~CastSinkExtraData() = default;
+
+}  // namespace media_router