Index: src/wp-includes/js/wp-custom-header.js
===================================================================
--- src/wp-includes/js/wp-custom-header.js	(revision 39144)
+++ src/wp-includes/js/wp-custom-header.js	(working copy)
@@ -61,7 +61,8 @@
 	}
 
 	function nativeHandler( settings ) {
-		var video = document.createElement( 'video' );
+		var video = document.createElement( 'video' ),
+			button = document.createElement( 'button' );
 
 		video.id = 'wp-custom-header-video';
 		video.autoplay = 'autoplay';
@@ -70,10 +71,18 @@
 		video.width = settings.width;
 		video.height = settings.height;
 
-		video.addEventListener( 'click', function() {
+		button.setAttribute( 'type', 'button' );
+		button.setAttribute( 'id', 'wp-custom-header-video-button' );
+		button.setAttribute( 'class', 'wp-custom-header-video-button' );
+		button.setAttribute( 'aria-hidden', true );
+		button.innerHTML = 'Pause';
+
+		button.addEventListener( 'click', function() {
 			if ( video.paused ) {
+				button.innerHTML = 'Pause';
 				video.play();
 			} else {
+				button.innerHTML = 'Play';
 				video.pause();
 			}
 		});
@@ -80,6 +89,7 @@
 
 		settings.container.innerHTML = '';
 		settings.container.appendChild( video );
+		settings.container.appendChild( button );
 		video.src = settings.videoUrl;
 	}
 
Index: src/wp-includes/theme.php
===================================================================
--- src/wp-includes/theme.php	(revision 39144)
+++ src/wp-includes/theme.php	(working copy)
@@ -1422,7 +1422,7 @@
 	}
 
 	return sprintf(
-		'<div id="wp-custom-header" class="wp-custom-header">%s</div>',
+		'<div id="wp-custom-header" class="wp-custom-header" aria-hidden="true">%s</div>',
 		get_header_image_tag()
 	);
 }