Record metrics for permission prompt acceptance vs. user gesture.

chrome/browser/permissions/permission_request.cc

 // Copyright 2015 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.
 
 #include "chrome/browser/permissions/permission_request.h"
 
 #include "ui/gfx/vector_icons_public.h"
 
 gfx::VectorIconId PermissionRequest::GetVectorIconId() const {
   return gfx::VectorIconId::VECTOR_ICON_NONE;
 }
 
 PermissionRequestType PermissionRequest::GetPermissionRequestType() const {
   return PermissionRequestType::UNKNOWN;
 }
+
+PermissionRequestGestureType PermissionRequest::GetGestureType() const {
+  return PermissionRequestGestureType::UNKNOWN;
+}