mash: Remove app_driver.

mash/public/interfaces/launchable.mojom

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 module mash.mojom;
 
 const uint32 kWindow = 1;
-const uint32 kDocument = 2;
-const uint32 kIncognitoWindow = 3;
+const uint32 kIncognitoWindow = 2;
 
 enum LaunchMode {
   DEFAULT,
   REUSE,
   MAKE_NEW
 };
 
 interface Launchable {
   // Launches something. The implementor decides what constitutes a "thing." If
   // an instance of the thing is already present, the implementor may decide to
   // re-select that thing instead of making another, depending on the value of
   // |how|. In many windowing cases, the thing is a window.
   Launch(uint32 what, LaunchMode how);
 };