Add media router common classes and unittests.

chrome/browser/media/router/media_route.cc

+// Copyright 2015 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_route.h"
+
+#include "base/logging.h"
+#include "chrome/browser/media/router/media_source.h"
+
+namespace media_router {
+
+const int64 kInvalidRouteRequestId = -1;

[mark a. foltz, 2015/03/02 21:40:08]

s/int64/RouteRequestId/

[Kevin M, 2015/03/03 21:53:18]

Done.

+
+MediaRoute::MediaRoute(const MediaRouteId& media_route_id,
+                       const MediaSource& media_source,
+                       const MediaSinkId& sink_id,
+                       const std::string& description,
+                       bool is_local)
+    : media_route_id_(media_route_id),
+      media_source_(media_source),
+      sink_id_(sink_id),
+      description_(description),
+      is_local_(is_local),
+      state_(MEDIA_ROUTE_STATE_NEW) {

[mark a. foltz, 2015/03/02 21:40:08]

description_ and state_ would seem to be mutable over the lifetime of a route.

Do they need setters?

[Kevin M, 2015/03/03 21:53:18]

The Media Route object is used to communicate the state of a MR at a given point
of time, so they should be immutable. If the state of a MR changes, then the
component extension will simply send a new MediaRoute object instead of mutating
a preexisting object.

[mark a. foltz, 2015/03/04 06:22:58]

(1) This semantic should be documented in the header - something along the lines
of this object capturing the state of the route at a given point in time.

(2) How does code holding references to existing routes get notified/updated
when they change state?

[Kevin M, 2015/03/04 23:33:32]

1. See the new comment for MediaRoute.
2. Also see the new comment. There is no code that holds references to routes;
MediaRoute objects are short lived and are only used to carry route data between
the MRPM and the WebUI.

+}
+
+MediaRoute::~MediaRoute() {
+}
+
+bool MediaRoute::operator==(const MediaRoute& other) const {
+  return media_route_id_ == other.media_route_id_ &&

[mark a. foltz, 2015/03/02 21:40:08]

The declaration states that route_ids are unique among all instances, so
comparison-by-id should be sufficient?

[Kevin M, 2015/03/03 21:53:18]

Done.

+         media_source_ == other.media_source_ &&
+         sink_id_ == sink_id_ &&
+         description_ == other.description_ &&
+         is_local_ == other.is_local_ &&
+         state_ == other.state_;
+}
+
+bool MediaRoute::operator!=(const MediaRoute& other) const {
+  return !(*this == other);
+}
+
+// static
+scoped_ptr<MediaRouteResponse> MediaRouteResponse::Success(
+    const RouteRequestId& request_id, const MediaRoute& route) {
+  return make_scoped_ptr(new MediaRouteResponse(request_id, route));
+}
+
+// static
+scoped_ptr<MediaRouteResponse> MediaRouteResponse::Error(
+    const RouteRequestId& request_id, const std::string& error) {
+  return make_scoped_ptr(new MediaRouteResponse(request_id, error));
+}
+
+MediaRouteResponse::~MediaRouteResponse() {
+}
+
+MediaRouteResponse::MediaRouteResponse(
+    const RouteRequestId& request_id, const MediaRoute& route)
+    : request_id_(request_id), route_(new MediaRoute(route)) {
+}
+
+MediaRouteResponse::MediaRouteResponse(
+    const RouteRequestId& request_id, const std::string& error)
+    : request_id_(request_id), error_(error) {
+}
+
+MediaRouteResponse::MediaRouteResponse(const MediaRouteResponse& other)
+    : request_id_(other.request_id_), error_(other.error_) {
+  if (other.route_.get())
+    route_.reset(new MediaRoute(*other.route_));
+}
+
+}  // namespace media_router