[Mojo Video Capture] Cleanup naming of classes/files in services/video_capture

services/video_capture/device_client_media_to_mojo_adapter.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/device_client_media_to_mojo_adapter.h"
-
-namespace video_capture {
-
-DeviceClientMediaToMojoAdapter::DeviceClientMediaToMojoAdapter(
-    std::unique_ptr<media::VideoCaptureDevice::Client> client)
-    : client_(std::move(client)) {}
-
-DeviceClientMediaToMojoAdapter::~DeviceClientMediaToMojoAdapter() = default;
-
-}  // namespace video_capture