examples: drop prefix webkit-playsinline

examples/webgl_materials_video.html

@@ -57,7 +57,7 @@
 			playing <a href="http://durian.blender.org/" target="_blank" rel="noopener">sintel</a> trailer
 		</div>
 
-		<video id="video" loop crossOrigin="anonymous" webkit-playsinline style="display:none">
+		<video id="video" loop crossOrigin="anonymous" playsinline style="display:none">
 			<source src="textures/sintel.ogv" type='video/ogg; codecs="theora, vorbis"'>
 			<source src="textures/sintel.mp4" type='video/mp4; codecs="avc1.42E01E, mp4a.40.2"'>
 		</video>