Texture: Honor ImageBitmap in serializeImage().

src/textures/Texture.js

@@ -339,7 +339,8 @@ Object.defineProperty( Texture.prototype, "needsUpdate", {
 function serializeImage( image ) {
 
 	if ( ( typeof HTMLImageElement !== 'undefined' && image instanceof HTMLImageElement ) ||
-		( typeof HTMLCanvasElement !== 'undefined' && image instanceof HTMLCanvasElement ) ) {
+		( typeof HTMLCanvasElement !== 'undefined' && image instanceof HTMLCanvasElement ) ||
+		( typeof ImageBitmap !== 'undefined' && image instanceof ImageBitmap ) ) {
 
 		// default images