Fixed webvr_sandbox outline on mobiles.

examples/webvr_sandbox.html

@@ -125,7 +125,7 @@
 				//
 
 				renderer = new THREE.WebGLRenderer( { antialias: true } );
-				renderer.setClearColor( 0x000000 );
+				renderer.autoClear = false;
 				renderer.setPixelRatio( window.devicePixelRatio );
 				renderer.setSize( window.innerWidth, window.innerHeight );
 				renderer.shadowMap.enabled = true;