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

services/video_capture/mock_media_device_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 "services/video_capture/mock_video_capture_device_impl.h"
+#include "services/video_capture/mock_media_device_impl.h"
 
 namespace video_capture {
 
-MockVideoCaptureDeviceImpl::MockVideoCaptureDeviceImpl(
-    mojom::MockVideoCaptureDeviceRequest request)
+MockMediaDeviceImpl::MockMediaDeviceImpl(mojom::MockMediaDeviceRequest request)
     : binding_(this, std::move(request)) {}
 
-MockVideoCaptureDeviceImpl::~MockVideoCaptureDeviceImpl() = default;
+MockMediaDeviceImpl::~MockMediaDeviceImpl() = default;
 
-void MockVideoCaptureDeviceImpl::AllocateAndStart(
-    mojom::MockDeviceClientPtr client) {
+void MockMediaDeviceImpl::AllocateAndStart(mojom::MockDeviceClientPtr client) {
   AllocateAndStartPtr(&client);
 }
 
 }  // namespace video_capture