Use a decoupled clock for triangles intro to avoid startup freezes on broken audio device

osu.Game/Screens/Menu/IntroScreen.cs

@@ -165,7 +165,7 @@ namespace osu.Game.Screens.Menu
 
         protected override BackgroundScreen CreateBackground() => new BackgroundScreenBlack();
 
-        protected void StartTrack()
+        protected virtual void StartTrack()
         {
             // Only start the current track if it is the menu music. A beatmap's track is started when entering the Main Menu.
             if (UsingThemedIntro)

osu.Game/Screens/Menu/IntroTriangles.cs

@@ -41,6 +41,8 @@ namespace osu.Game.Screens.Menu
 
         private Sample welcome;
 
+        private DecoupleableInterpolatingFramedClock decoupledClock;
+
         [BackgroundDependencyLoader]
         private void load()
         {
@@ -56,10 +58,18 @@ namespace osu.Game.Screens.Menu
             {
                 PrepareMenuLoad();
 
+                decoupledClock = new DecoupleableInterpolatingFramedClock
+                {
+                    IsCoupled = false
+                };
+
+                if (UsingThemedIntro)
+                    decoupledClock.ChangeSource(Track);
+
                 LoadComponentAsync(new TrianglesIntroSequence(logo, background)
                 {
                     RelativeSizeAxes = Axes.Both,
-                    Clock = new FramedClock(UsingThemedIntro ? Track : null),
+                    Clock = decoupledClock,
                     LoadMenu = LoadMenu
                 }, t =>
                 {
@@ -78,6 +88,12 @@ namespace osu.Game.Screens.Menu
             background.FadeOut(100);
         }
 
+        protected override void StartTrack()
+        {
+            if (UsingThemedIntro)
+                decoupledClock.Start();
+        }
+
         private class TrianglesIntroSequence : CompositeDrawable
         {
             private readonly OsuLogo logo;