Package video capture skeleton as Mojo Shell Service

services/video_capture/video_capture_device_factory_impl.cc

 // 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.
 
 #include "base/logging.h"
 #include "services/video_capture/video_capture_device_factory_impl.h"
 
 namespace video_capture {
 
 void VideoCaptureDeviceFactoryImpl::EnumerateDeviceDescriptors(
     const EnumerateDeviceDescriptorsCallback& callback) {
-  NOTIMPLEMENTED();
+  std::vector<mojom::VideoCaptureDeviceDescriptorPtr> empty_descriptors;
+  callback.Run(std::move(empty_descriptors));
 }
 
 void VideoCaptureDeviceFactoryImpl::GetSupportedFormats(
     mojom::VideoCaptureDeviceDescriptorPtr device_descriptor,
     const GetSupportedFormatsCallback& callback) {
   NOTIMPLEMENTED();
 }
 
 void VideoCaptureDeviceFactoryImpl::CreateDevice(
     mojom::VideoCaptureDeviceDescriptorPtr device_descriptor,
     mojom::VideoCaptureDeviceRequest device_request) {
   NOTIMPLEMENTED();
 }
 
 }  // namespace video_capture