CrOS GMC: Fix a bug where artist is still visible when empty.

Remove artist visibility change in OnNewMediaSession since artist
visibility is set in SetArtist().

Change-Id: I455c0a169b06e320db3a0f758dd5b48d59881a8b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2533283
Commit-Queue: Jazz Xu <jazzhsu@chromium.org>
Auto-Submit: Jazz Xu <jazzhsu@chromium.org>
Reviewed-by: Tetsui Ohkubo <tetsui@chromium.org>
Cr-Commit-Position: refs/heads/master@{#826909}

ash/system/media/unified_media_controls_controller_unittest.cc

@@ -440,6 +440,11 @@ TEST_F(UnifiedMediaControlsControllerTest, MediaControlsEmptyState) {
   EnableAction(MediaSessionAction::kPreviousTrack);
   EnableAction(MediaSessionAction::kNextTrack);
 
+  media_session::MediaMetadata metadata;
+  metadata.title = base::ASCIIToUTF16("title");
+  metadata.artist = base::ASCIIToUTF16("artist");
+  controller()->MediaSessionMetadataChanged(metadata);
+
   EXPECT_TRUE(artist_label()->GetVisible());
   EXPECT_FALSE(artwork_view()->GetVisible());
   for (views::View* button : button_row()->children())
@@ -472,7 +477,6 @@ TEST_F(UnifiedMediaControlsControllerTest, MediaControlsEmptyState) {
   SimulateNewMediaSessionWithData(request_id);
   EXPECT_FALSE(IsMediaControlsInEmptyState());
 
-  EXPECT_TRUE(artist_label()->GetVisible());
   EXPECT_FALSE(artwork_view()->GetVisible());
   for (views::View* button : button_row()->children())
     EXPECT_TRUE(button->GetEnabled());

ash/system/media/unified_media_controls_view.cc

@@ -367,7 +367,6 @@ void UnifiedMediaControlsView::OnNewMediaSession() {
   is_in_empty_state_ = false;
   title_label_->SetEnabledColor(AshColorProvider::Get()->GetContentLayerColor(
       AshColorProvider::ContentLayerType::kTextColorPrimary));
-  artist_label_->SetVisible(true);
   drop_down_icon_->SetVisible(true);
 
   for (views::View* button : button_row_->children())