[Mojo Video Capture] Use string keys instead of VideoCaptureDeviceDescriptor

services/video_capture/video_capture_service.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 "services/video_capture/video_capture_service.h"
 
 #include "base/message_loop/message_loop.h"
 #include "media/capture/video/fake_video_capture_device_factory.h"
 #include "media/capture/video/video_capture_buffer_pool.h"
 #include "media/capture/video/video_capture_buffer_tracker.h"
 #include "media/capture/video/video_capture_jpeg_decoder.h"
 #include "services/service_manager/public/cpp/interface_registry.h"
 #include "services/video_capture/device_factory_media_to_mojo_adapter.h"
 #include "services/video_capture/mock_device_factory.h"
 
 namespace {
+
 // TODO(chfremer): Replace with an actual decoder factory.
 // https://crbug.com/584797
 std::unique_ptr<media::VideoCaptureJpegDecoder> CreateJpegDecoder() {
   return nullptr;
 }
 
 }  // anonymous namespace
 
 namespace video_capture {
 
@@ skipping 74 matching lines @@
   // We keep a pointer to the MockDeviceFactory as a member so that we can
   // invoke its AddMockDevice(). Ownership of the MockDeviceFactory is moved
   // to the DeviceFactoryMediaToMojoAdapter.
   mock_device_factory_ = mock_device_factory.get();
   mock_device_factory_adapter_ =
       base::MakeUnique<DeviceFactoryMediaToMojoAdapter>(
           std::move(mock_device_factory), base::Bind(&CreateJpegDecoder));
 }
 
 }  // namespace video_capture