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

services/video_capture/public/interfaces/video_capture_device_proxy.mojom

-// 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.
-
-module video_capture.mojom;
-
-import "media/capture/mojo/video_capture_types.mojom";
-import "services/video_capture/public/interfaces/video_capture_settings.mojom";
-import "services/video_capture/public/interfaces/video_frame_receiver.mojom";
-
-// Represents access to a video capture device available on the machine.
-// Note: Instead of offering an explicit Stop() method, the device
-// is stopped automatically when the message pipe corresponding to either the
-// VideoCaptureDeviceProxy or the given VideoFrameReceiver is closed.
-// The frames deliverd to |receiver| are guaranteed to use I420 encoding and
-// are backed by Mojo shared buffers.
-interface VideoCaptureDeviceProxy {
-  Start(VideoCaptureSettings requested_settings,
-        VideoFrameReceiver receiver);
-};