Add `editor_stylesheets` filter to `get_editor_stylesheets()`.

props danielbachhuber, MikeHansenMe.
fixes #31672.
Built from https://develop.svn.wordpress.org/trunk@32928


git-svn-id: http://core.svn.wordpress.org/trunk@32899 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/theme.php

@@ -1499,7 +1499,14 @@ function get_editor_stylesheets() {
 			}
 		}
 	}
-	return $stylesheets;
+	/**
+	 * Filter the array of stylesheets applied to the editor.
+	 *
+	 * @since 4.3.0
+	 *
+	 * @param array $stylesheets Array of stylesheets to be applied to the editor.
+	 */
+	return apply_filters( 'editor_stylesheets', $stylesheets );
 }
 
 /**

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.3-alpha-32927';
+$wp_version = '4.3-alpha-32928';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.