Index: wp-includes/media.php
===================================================================
--- wp-includes/media.php	(revision 20062)
+++ wp-includes/media.php	(working copy)
@@ -1158,7 +1158,7 @@
 			return '';
 
 		$rawattr = $attr;
-		$attr = wp_parse_args( $attr, wp_embed_defaults() );
+		$attr = wp_parse_args( $attr, wp_embed_defaults( $url ) );
 
 		// kses converts & into & and we need to undo this
 		// See http://core.trac.wordpress.org/ticket/11311
@@ -1323,7 +1323,7 @@
  *
  * @return array Default embed parameters.
  */
-function wp_embed_defaults() {
+function wp_embed_defaults( $url = '' ) {
 	if ( !empty($GLOBALS['content_width']) )
 		$theme_width = (int) $GLOBALS['content_width'];
 
@@ -1343,7 +1343,7 @@
 	return apply_filters( 'embed_defaults', array(
 		'width'  => $width,
 		'height' => $height,
-	) );
+	) , $url );
 }
 
 /**
Index: wp-includes/comment-template.php
===================================================================
--- wp-includes/comment-template.php	(revision 20062)
+++ wp-includes/comment-template.php	(working copy)
@@ -1544,6 +1544,7 @@
 		'title_reply_to'       => __( 'Leave a Reply to %s' ),
 		'cancel_reply_link'    => __( 'Cancel reply' ),
 		'label_submit'         => __( 'Post Comment' ),
+		'tabindex'             => '',
 	);
 
 	$args = wp_parse_args( $args, apply_filters( 'comment_form_defaults', $defaults ) );
@@ -1575,7 +1576,7 @@
 						<?php echo apply_filters( 'comment_form_field_comment', $args['comment_field'] ); ?>
 						<?php echo $args['comment_notes_after']; ?>
 						<p class="form-submit">
-							<input name="submit" type="submit" id="<?php echo esc_attr( $args['id_submit'] ); ?>" value="<?php echo esc_attr( $args['label_submit'] ); ?>" />
+							<input name="submit" type="submit" id="<?php echo esc_attr( $args['id_submit'] ); ?>" value="<?php echo esc_attr( $args['label_submit'] ); ?>" tabindex="<?php echo esc_attr( $args['tabindex'] ); ?>" />
 							<?php comment_id_fields( $post_id ); ?>
 						</p>
 						<?php do_action( 'comment_form', $post_id ); ?>
Index: wp-includes/class-oembed.php
===================================================================
--- wp-includes/class-oembed.php	(revision 20062)
+++ wp-includes/class-oembed.php	(working copy)
@@ -157,7 +157,7 @@
 	 * @return bool|object False on failure, otherwise the result in the form of an object.
 	 */
 	function fetch( $provider, $url, $args = '' ) {
-		$args = wp_parse_args( $args, wp_embed_defaults() );
+		$args = wp_parse_args( $args, wp_embed_defaults( $url ) );
 
 		$provider = add_query_arg( 'maxwidth', (int) $args['width'], $provider );
 		$provider = add_query_arg( 'maxheight', (int) $args['height'], $provider );