Reland "GMC: Add IPC for switching the audio output device"

This is a reland of f300ac05

The original change added a method to a mojom interface but neglected to
implemnet this method for a class in ChromeOS. This reland adds the
missing implementation that caused builds to fail.

Original change's description:
> GMC: Add IPC for switching the audio output device
>
> This change adds methods used by the global media controls ui for
> switching the audio output device used by a page.
>
> MediaController::SetAudioSinkId was created allowing the
> MediaNotificationService to route the audio output of a
> MediaNotificationSession to a specified audio device.
>
> Mojo interfaces were expanded to allow for this IPC between the
> controller and session.
>
> Bug: 1096243
> Change-Id: Icd0ad17d6ef88ec297444b8b2cbc7ddda6c2c4c9
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2295799
> Commit-Queue: Noah Rose Ledesma <noahrose@google.com>
> Reviewed-by: Sergey Ulanov <sergeyu@chromium.org>
> Reviewed-by: Sean Topping <seantopping@chromium.org>
> Reviewed-by: Daniel Cheng <dcheng@chromium.org>
> Reviewed-by: Becca Hughes <beccahughes@chromium.org>
> Reviewed-by: Tommy Steimel <steimel@chromium.org>
> Auto-Submit: Noah Rose Ledesma <noahrose@google.com>
> Cr-Commit-Position: refs/heads/master@{#792935}

Bug: 1096243
Change-Id: I0dad44fc7d1c8daac50519e8625a3cc2150fa34c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2328034Reviewed-by: Sean Topping <seantopping@chromium.org>
Reviewed-by: Yue Li <updowndota@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: Becca Hughes <beccahughes@chromium.org>
Reviewed-by: Tommy Steimel <steimel@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Commit-Queue: Noah Rose Ledesma <noahrose@google.com>
Cr-Commit-Position: refs/heads/master@{#794619}

chrome/browser/ui/global_media_controls/media_notification_service.cc

@@ -221,7 +221,9 @@ bool MediaNotificationService::Session::IsPlaying() {
   return is_playing_;
 }
 
-void MediaNotificationService::Session::SetAudioSinkId(const std::string& id) {}
+void MediaNotificationService::Session::SetAudioSinkId(const std::string& id) {
+  controller_->SetAudioSinkId(id);
+}
 
 // static
 void MediaNotificationService::Session::RecordDismissReason(

chromecast/browser/cast_media_blocker_unittest.cc

@@ -56,6 +56,7 @@ class MockMediaSession : public content::MediaSession {
   MOCK_METHOD1(ScrubTo, void(base::TimeDelta));
   MOCK_METHOD0(EnterPictureInPicture, void());
   MOCK_METHOD0(ExitPictureInPicture, void());
+  MOCK_METHOD1(SetAudioSinkId, void(const base::Optional<std::string>& id));
 
  private:
   DISALLOW_COPY_AND_ASSIGN(MockMediaSession);
@@ -105,7 +106,6 @@ class CastMediaBlockerTest : public content::RenderViewHostTestHarness {
   DISALLOW_COPY_AND_ASSIGN(CastMediaBlockerTest);
 };
 
-
 TEST_F(CastMediaBlockerTest, Block_Unblock_Suspended) {
   // Testing block/unblock operations do nothing if media never plays.
   EXPECT_CALL(*media_session_, Suspend(_)).Times(0);

chromeos/services/assistant/media_session/assistant_media_session.h

@@ -59,6 +59,7 @@ class COMPONENT_EXPORT(ASSISTANT_SERVICE) AssistantMediaSession
   void ScrubTo(base::TimeDelta seek_time) override {}
   void EnterPictureInPicture() override {}
   void ExitPictureInPicture() override {}
+  void SetAudioSinkId(const base::Optional<std::string>& sink_id) override {}
 
   // Requests/abandons audio focus to the AudioFocusManager.
   void RequestAudioFocus(media_session::mojom::AudioFocusType audio_focus_type);

content/browser/media/session/media_session_impl.cc

@@ -1071,6 +1071,8 @@ void MediaSessionImpl::ExitPictureInPicture() {
       normal_players_.begin()->first.player_id);
 }
 
+void MediaSessionImpl::SetAudioSinkId(const base::Optional<std::string>& id) {}
+
 void MediaSessionImpl::GetMediaImageBitmap(
     const media_session::MediaImage& image,
     int minimum_size_px,

content/browser/media/session/media_session_impl.h

@@ -253,6 +253,10 @@ class MediaSessionImpl : public MediaSession,
   // Exit picture-in-picture.
   void ExitPictureInPicture() override;
 
+  // Routes the audio from this Media Session to the given output device. If
+  // |id| is null, we will route to the default output device.
+  void SetAudioSinkId(const base::Optional<std::string>& id) override;
+
   // Downloads the bitmap version of a MediaImage at least |minimum_size_px|
   // and closest to |desired_size_px|. If the download failed, was too small or
   // the image did not come from the media session then returns a null image.

fuchsia/engine/browser/media_player_impl_unittest.cc

@@ -36,6 +36,7 @@ class FakeMediaSession : public content::MediaSession {
   MOCK_METHOD1(ScrubTo, void(base::TimeDelta));
   MOCK_METHOD0(EnterPictureInPicture, void());
   MOCK_METHOD0(ExitPictureInPicture, void());
+  MOCK_METHOD1(SetAudioSinkId, void(const base::Optional<std::string>& id));
 
   // content::MediaSession APIs faked to implement testing behaviour.
   MOCK_METHOD1(DidReceiveAction,

services/media_session/media_controller.cc

@@ -291,6 +291,13 @@ void MediaController::ExitPictureInPicture() {
     session_->ipc()->ExitPictureInPicture();
 }
 
+void MediaController::SetAudioSinkId(const base::Optional<std::string>& id) {
+  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
+
+  if (session_)
+    session_->ipc()->SetAudioSinkId(id);
+}
+
 void MediaController::SetMediaSession(AudioFocusRequest* session) {
   DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
 

services/media_session/media_controller.h

@@ -53,6 +53,7 @@ class MediaController : public mojom::MediaController,
   void ScrubTo(base::TimeDelta seek_time) override;
   void EnterPictureInPicture() override;
   void ExitPictureInPicture() override;
+  void SetAudioSinkId(const base::Optional<std::string>& id) override;
 
   // mojom::MediaSessionObserver overrides.
   void MediaSessionInfoChanged(

services/media_session/public/cpp/test/mock_media_session.h

@@ -154,6 +154,7 @@ class COMPONENT_EXPORT(MEDIA_SESSION_TEST_SUPPORT_CPP) MockMediaSession
   void ScrubTo(base::TimeDelta scrub_to) override;
   void EnterPictureInPicture() override;
   void ExitPictureInPicture() override;
+  void SetAudioSinkId(const base::Optional<std::string>& id) override {}
 
   void SetIsControllable(bool value);
   void SetPreferStop(bool value) { prefer_stop_ = value; }

services/media_session/public/cpp/test/test_media_controller.h

@@ -155,6 +155,7 @@ class COMPONENT_EXPORT(MEDIA_SESSION_TEST_SUPPORT_CPP) TestMediaController
   void ScrubTo(base::TimeDelta seek_time) override {}
   void EnterPictureInPicture() override;
   void ExitPictureInPicture() override;
+  void SetAudioSinkId(const base::Optional<std::string>& id) override {}
 
   int toggle_suspend_resume_count() const {
     return toggle_suspend_resume_count_;

services/media_session/public/mojom/media_controller.mojom

@@ -83,6 +83,10 @@ interface MediaController {
 
   // Exit picture-in-picture.
   ExitPictureInPicture();
+
+  // Routes the audio from this Media Session to the given output device. If
+  // |id| is null, we will route to the default output device.
+  SetAudioSinkId(string? id);
 };
 
 // The observer for observing media controller events. This is different to a

services/media_session/public/mojom/media_session.mojom

@@ -9,7 +9,7 @@ import "mojo/public/mojom/base/time.mojom";
 import "ui/gfx/geometry/mojom/geometry.mojom";
 import "url/mojom/url.mojom";
 
-// Next MinVersion: 9
+// Next MinVersion: 10
 
 [Extensible]
 enum MediaPlaybackState {
@@ -146,6 +146,11 @@ struct MediaSessionInfo {
 
   // The audio/video state of the Media Session (if known).
   [MinVersion=8] MediaAudioVideoState audio_video_state;
+
+  // The audio_sink_id tells the client the device_id of the audio output device
+  // being used for this media session. A null audio_sink_id implies that the
+  // default device is being used.
+  [MinVersion=9] string? audio_sink_id;
 };
 
 // Contains debugging information about a MediaSession. This will be displayed
@@ -188,7 +193,7 @@ interface MediaSessionObserver {
 // WebContents or ARC app.
 // TODO(https://crbug.com/875004): migrate media session from content/public
 // to mojo.
-// Next Method ID: 17
+// Next Method ID: 18
 interface MediaSession {
   [Extensible]
   enum SuspendType {
@@ -270,4 +275,8 @@ interface MediaSession {
 
   // Exit picture-in-picture.
   ExitPictureInPicture@16();
+
+  // Routes the audio from this Media Session to the given output device. If
+  // |id| is null, we will route to the default output device.
+  SetAudioSinkId@17(string? id);
 };