System Media Controls: Add title/artist/album metadata on Mac

This CL adds media session metadata (title, artist, and album) to the
Now Playing Info Center when available.

Bug: 936513
Change-Id: Id95728fd4ad1a06b242f6596475315fa65ec913c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1902509Reviewed-by: Becca Hughes <beccahughes@chromium.org>
Commit-Queue: Tommy Steimel <steimel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#713232}

components/system_media_controls/mac/now_playing_info_center_delegate.h

@@ -24,6 +24,10 @@ class API_AVAILABLE(macos(10.12.2)) NowPlayingInfoCenterDelegate {
 
   // Part of the implementation of SystemMediaControls.
   void SetPlaybackStatus(SystemMediaControls::PlaybackStatus status);
+  void SetTitle(const base::string16& title);
+  void SetArtist(const base::string16& artist);
+  void SetAlbum(const base::string16& album);
+  void ClearMetadata();
 
  private:
   base::scoped_nsobject<NowPlayingInfoCenterDelegateCocoa>

components/system_media_controls/mac/now_playing_info_center_delegate.mm

@@ -6,6 +6,7 @@
 
 #import <MediaPlayer/MediaPlayer.h>
 
+#include "base/strings/sys_string_conversions.h"
 #include "components/system_media_controls/mac/now_playing_info_center_delegate_cocoa.h"
 
 namespace system_media_controls {
@@ -47,5 +48,24 @@ void NowPlayingInfoCenterDelegate::SetPlaybackStatus(
   [now_playing_info_center_delegate_cocoa_ setPlaybackState:state];
 }
 
+void NowPlayingInfoCenterDelegate::SetTitle(const base::string16& title) {
+  [now_playing_info_center_delegate_cocoa_
+      setTitle:base::SysUTF16ToNSString(title)];
+}
+
+void NowPlayingInfoCenterDelegate::SetArtist(const base::string16& artist) {
+  [now_playing_info_center_delegate_cocoa_
+      setArtist:base::SysUTF16ToNSString(artist)];
+}
+
+void NowPlayingInfoCenterDelegate::SetAlbum(const base::string16& album) {
+  [now_playing_info_center_delegate_cocoa_
+      setAlbum:base::SysUTF16ToNSString(album)];
+}
+
+void NowPlayingInfoCenterDelegate::ClearMetadata() {
+  [now_playing_info_center_delegate_cocoa_ clearMetadata];
+}
+
 }  // namespace internal
 }  // namespace system_media_controls

components/system_media_controls/mac/now_playing_info_center_delegate_cocoa.h

@@ -18,6 +18,12 @@ API_AVAILABLE(macos(10.12.2))
 
 // Called by the NowPlayingInfoCenterDelegateImpl to set metadata.
 - (void)setPlaybackState:(MPNowPlayingPlaybackState)state;
+- (void)setTitle:(NSString*)title;
+- (void)setArtist:(NSString*)artist;
+- (void)setAlbum:(NSString*)album;
+
+// Sets all metadata to default values.
+- (void)clearMetadata;
 
 @end
 

components/system_media_controls/mac/now_playing_info_center_delegate_cocoa.mm

@@ -43,6 +43,26 @@
   [self updateNowPlayingInfo];
 }
 
+- (void)setTitle:(NSString*)title {
+  [nowPlayingInfo_ setObject:title forKey:MPMediaItemPropertyTitle];
+  [self updateNowPlayingInfo];
+}
+
+- (void)setArtist:(NSString*)artist {
+  [nowPlayingInfo_ setObject:artist forKey:MPMediaItemPropertyArtist];
+  [self updateNowPlayingInfo];
+}
+
+- (void)setAlbum:(NSString*)album {
+  [nowPlayingInfo_ setObject:album forKey:MPMediaItemPropertyAlbumTitle];
+  [self updateNowPlayingInfo];
+}
+
+- (void)clearMetadata {
+  [self initializeNowPlayingInfoValues];
+  [self updateNowPlayingInfo];
+}
+
 - (void)initializeNowPlayingInfoValues {
   [nowPlayingInfo_ setObject:[NSNumber numberWithDouble:0]
                       forKey:MPNowPlayingInfoPropertyElapsedPlaybackTime];
@@ -56,6 +76,7 @@
   [nowPlayingInfo_ setObject:@"Chromium" forKey:MPMediaItemPropertyTitle];
 #endif
   [nowPlayingInfo_ setObject:@"" forKey:MPMediaItemPropertyArtist];
+  [nowPlayingInfo_ setObject:@"" forKey:MPMediaItemPropertyAlbumTitle];
 }
 
 - (void)updateNowPlayingInfo {

components/system_media_controls/mac/system_media_controls_mac.h

@@ -38,12 +38,12 @@ class API_AVAILABLE(macos(10.12.2)) SystemMediaControlsMac
   void SetIsPlayPauseEnabled(bool value) override;
   void SetIsStopEnabled(bool value) override;
   void SetPlaybackStatus(PlaybackStatus status) override;
-  void SetTitle(const base::string16& title) override {}
-  void SetArtist(const base::string16& artist) override {}
-  void SetAlbum(const base::string16& album) override {}
+  void SetTitle(const base::string16& title) override;
+  void SetArtist(const base::string16& artist) override;
+  void SetAlbum(const base::string16& album) override;
   void SetThumbnail(const SkBitmap& bitmap) override {}
   void ClearThumbnail() override {}
-  void ClearMetadata() override {}
+  void ClearMetadata() override;
   void UpdateDisplay() override {}
 
  private:

components/system_media_controls/mac/system_media_controls_mac.mm

@@ -58,5 +58,21 @@ void SystemMediaControlsMac::SetPlaybackStatus(PlaybackStatus status) {
   now_playing_info_center_delegate_.SetPlaybackStatus(status);
 }
 
+void SystemMediaControlsMac::SetTitle(const base::string16& title) {
+  now_playing_info_center_delegate_.SetTitle(title);
+}
+
+void SystemMediaControlsMac::SetArtist(const base::string16& artist) {
+  now_playing_info_center_delegate_.SetArtist(artist);
+}
+
+void SystemMediaControlsMac::SetAlbum(const base::string16& album) {
+  now_playing_info_center_delegate_.SetAlbum(album);
+}
+
+void SystemMediaControlsMac::ClearMetadata() {
+  now_playing_info_center_delegate_.ClearMetadata();
+}
+
 }  // namespace internal
 }  // namespace system_media_controls