Add hints for potential overlay promotion on android.

cc/ipc/transferable_resource.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 cc.mojom;
 
 import "gpu/ipc/common/mailbox_holder.mojom";
 import "ui/gfx/geometry/mojo/geometry.mojom";
 
 enum ResourceFormat {
   RGBA_8888,
   RGBA_4444,
   BGRA_8888,
   ALPHA_8,
   LUMINANCE_8,
   RGB_565,
   ETC1,
 };
 
 // See cc/resources/transferable_resource.h.
 struct TransferableResource {
   uint32 id;
   ResourceFormat format;
   uint32 filter;
   gfx.mojom.Size size;
   gpu.mojom.MailboxHolder mailbox_holder;
   bool read_lock_fences_enabled;
   bool is_software;
   bool is_overlay_candidate;
+  bool is_backed_by_surface_texture;
+  bool wants_promotion_hint;
 };