Make player block exit if pausable

osu.Game.Tests/Visual/Gameplay/TestScenePause.cs

@@ -115,8 +115,9 @@ namespace osu.Game.Tests.Visual.Gameplay
         [Test]
         public void TestExitTooSoon()
         {
-            pauseAndConfirm();
+            AddStep("seek before gameplay", () => Player.GameplayClockContainer.Seek(-5000));
 
+            pauseAndConfirm();
             resume();
 
             AddStep("exit too soon", () => Player.Exit());
@@ -176,7 +177,9 @@ namespace osu.Game.Tests.Visual.Gameplay
         public void TestExitFromGameplay()
         {
             AddStep("exit", () => Player.Exit());
+            confirmPaused();
 
+            AddStep("exit", () => Player.Exit());
             confirmExited();
         }
 
@@ -214,6 +217,8 @@ namespace osu.Game.Tests.Visual.Gameplay
         [Test]
         public void TestRestartAfterResume()
         {
+            AddStep("seek before gameplay", () => Player.GameplayClockContainer.Seek(-5000));
+
             pauseAndConfirm();
             resumeAndConfirm();
             restart();

osu.Game/Screens/Play/Player.cs

@@ -536,6 +536,12 @@ namespace osu.Game.Screens.Play
                     return true;
             }
 
+            if (canPause)
+            {
+                Pause();
+                return true;
+            }
+
             // GameplayClockContainer performs seeks / start / stop operations on the beatmap's track.
             // as we are no longer the current screen, we cannot guarantee the track is still usable.
             GameplayClockContainer.StopUsingBeatmapClock();