[Cast MRP] Added logic to select an app ID based on device capabilities.

Bug: 1078435, b/155777247
Change-Id: Ic5ed0bd7766e367ca7526e9b95b461885d4bf8c7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2220909Reviewed-by: mark a. foltz <mfoltz@chromium.org>
Commit-Queue: John Williams <jrw@chromium.org>
Auto-Submit: John Williams <jrw@chromium.org>
Cr-Commit-Position: refs/heads/master@{#775771}

chrome/browser/media/router/providers/cast/cast_activity_manager.cc

@@ -160,9 +160,7 @@ void CastActivityManager::DoLaunchSession(DoLaunchSessionParams params) {
   const MediaRoute::Id& route_id = route.media_route_id();
   const MediaSinkInternal& sink = params.sink;
 
-  // TODO(crbug.com/904995): In the case of multiple app IDs (e.g. mirroring),
-  // we need to choose an appropriate app ID to launch based on capabilities.
-  std::string app_id = cast_source.GetAppIds()[0];
+  std::string app_id = ChooseAppId(cast_source, params.sink);
 
   DVLOG(2) << "Launching session with route ID = " << route_id
            << ", source ID = " << cast_source.source_id()
@@ -779,6 +777,20 @@ base::Optional<MediaSinkInternal> CastActivityManager::ConvertMirrorToCast(
   return base::nullopt;
 }
 
+std::string CastActivityManager::ChooseAppId(
+    const CastMediaSource& source,
+    const MediaSinkInternal& sink) const {
+  const auto sink_capabilities =
+      BitwiseOr<cast_channel::CastDeviceCapability>::FromBits(
+          sink.cast_data().capabilities);
+  for (const auto& info : source.app_infos()) {
+    if (sink_capabilities.HasAll(info.required_capabilities))
+      return info.app_id;
+  }
+  NOTREACHED() << "Can't determine app ID from capabilities.";
+  return source.app_infos()[0].app_id;
+}
+
 CastActivityManager::DoLaunchSessionParams::DoLaunchSessionParams(
     const MediaRoute& route,
     const CastMediaSource& cast_source,

chrome/browser/media/router/providers/cast/cast_activity_manager.h

@@ -270,6 +270,9 @@ class CastActivityManager : public CastActivityManagerBase,
   // If no conversion should occur, returns base::nullopt.
   base::Optional<MediaSinkInternal> ConvertMirrorToCast(int tab_id);
 
+  std::string ChooseAppId(const CastMediaSource& source,
+                          const MediaSinkInternal& sink) const;
+
   static ActivityRecordFactoryForTest* activity_record_factory_;
 
   base::flat_set<MediaSource::Id> route_queries_;

chrome/common/media_router/providers/cast/cast_media_source.cc

@@ -191,8 +191,8 @@ std::unique_ptr<CastMediaSource> CastMediaSourceForTabMirroring(
     const MediaSource::Id& source_id) {
   return std::make_unique<CastMediaSource>(
       source_id,
-      std::vector<CastAppInfo>({CastAppInfo(kCastStreamingAppId),
-                                CastAppInfo(kCastStreamingAudioAppId)}));
+      std::vector<CastAppInfo>({CastAppInfo::ForCastStreaming(),
+                                CastAppInfo::ForCastStreamingAudio()}));
 }
 
 std::unique_ptr<CastMediaSource> CastMediaSourceForDesktopMirroring(
@@ -200,7 +200,7 @@ std::unique_ptr<CastMediaSource> CastMediaSourceForDesktopMirroring(
   // TODO(https://crbug.com/849335): Add back audio-only devices for desktop
   // mirroring when proper support is implemented.
   return std::make_unique<CastMediaSource>(
-      source_id, std::vector<CastAppInfo>({CastAppInfo(kCastStreamingAppId)}));
+      source_id, std::vector<CastAppInfo>({CastAppInfo::ForCastStreaming()}));
 }
 
 // The logic shared by ParseCastUrl() and ParseLegacyCastUrl().
@@ -363,10 +363,23 @@ CastAppInfo::CastAppInfo(
     const std::string& app_id,
     BitwiseOr<cast_channel::CastDeviceCapability> required_capabilities)
     : app_id(app_id), required_capabilities(required_capabilities) {}
+
 CastAppInfo::~CastAppInfo() = default;
 
 CastAppInfo::CastAppInfo(const CastAppInfo& other) = default;
 
+// static
+CastAppInfo CastAppInfo::ForCastStreaming() {
+  return CastAppInfo(kCastStreamingAppId, {CastDeviceCapability::VIDEO_OUT,
+                                           CastDeviceCapability::AUDIO_OUT});
+}
+
+// static
+CastAppInfo CastAppInfo::ForCastStreamingAudio() {
+  return CastAppInfo(kCastStreamingAudioAppId,
+                     {CastDeviceCapability::AUDIO_OUT});
+}
+
 // static
 std::unique_ptr<CastMediaSource> CastMediaSource::FromMediaSource(
     const MediaSource& source) {

chrome/common/media_router/providers/cast/cast_media_source.h

@@ -44,12 +44,20 @@ class BitwiseOr {
     for (E e : values)
       Add(e);
   }
+  static constexpr BitwiseOr FromBits(T bits) { return BitwiseOr(bits); }
   bool empty() const { return bits_ == 0; }
+  T bits() const { return bits_; }
   void Add(E value) { bits_ |= Mask(value); }
+  bool Has(E value) const { return (bits_ & Mask(value)) != 0; }
+  bool HasAll(const BitwiseOr& other) const {
+    return (bits_ & other.bits_) == other.bits_;
+  }
   bool operator==(const BitwiseOr& other) const { return bits_ == other.bits_; }
   bool operator!=(const BitwiseOr& other) const { return *this != other; }
 
  private:
+  explicit constexpr BitwiseOr(T bits) : bits_(bits) {}
+
   static T Mask(E value) {
     const T result = static_cast<T>(value);
     DCHECK(static_cast<E>(result) == value);
@@ -60,12 +68,16 @@ class BitwiseOr {
 
 // Represents a Cast app and its capabilitity requirements.
 struct CastAppInfo {
-  explicit CastAppInfo(const std::string& app_id,
-                       BitwiseOr<cast_channel::CastDeviceCapability> = {});
+  explicit CastAppInfo(
+      const std::string& app_id,
+      BitwiseOr<cast_channel::CastDeviceCapability> required_capabilities);
   ~CastAppInfo();
 
   CastAppInfo(const CastAppInfo& other);
 
+  static CastAppInfo ForCastStreaming();
+  static CastAppInfo ForCastStreamingAudio();
+
   std::string app_id;
 
   // A bitset of capabilities required by the app.