internal/restorable: Bug fix: Test failed on macOS (Metal)

internal/driver/graphics.go

@@ -42,7 +42,6 @@ type Graphics interface {
 	NewImage(width, height int) (Image, error)
 	NewScreenFramebufferImage(width, height int) (Image, error)
 	Initialize() error
-	Reset() error
 	SetVsyncEnabled(enabled bool)
 	FramebufferYDirection() YDirection
 	NeedsRestoring() bool

internal/graphicscommand/command.go

@@ -662,10 +662,14 @@ func InitializeGraphicsDriverState() error {
 }
 
 // ResetGraphicsDriverState resets the current graphics driver state.
+// If the graphics driver doesn't have an API to reset, ResetGraphicsDriverState does nothing.
 func ResetGraphicsDriverState() error {
-	return runOnMainThread(func() error {
+	if r, ok := theGraphicsDriver.(interface{ Reset() error }); ok {
-		return theGraphicsDriver.Reset()
+		return runOnMainThread(func() error {
-	})
+			return r.Reset()
+		})
+	}
+	return nil
 }
 
 // MaxImageSize returns the maximum size of an image.

internal/graphicsdriver/metal/graphics.go

@@ -767,10 +767,6 @@ func (g *Graphics) Initialize() error {
 	return nil
 }
 
-func (g *Graphics) Reset() error {
-	panic("metal: Reset is not implemented")
-}
-
 func (g *Graphics) flushRenderCommandEncoderIfNeeded() {
 	if g.rce == (mtl.RenderCommandEncoder{}) {
 		return