Video Capture Mojo (1.4b): Implement ability to use fake device instance

services/video_capture/mock_device_descriptor_receiver.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_device_descriptor_receiver.h"
+
+namespace video_capture {
+
+MockDeviceDescriptorReceiver::MockDeviceDescriptorReceiver() = default;
+
+MockDeviceDescriptorReceiver::~MockDeviceDescriptorReceiver() = default;
+
+void MockDeviceDescriptorReceiver::HandleEnumerateDeviceDescriptorsCallback(
+    std::vector<mojom::VideoCaptureDeviceDescriptorPtr> descriptors) {
+  OnEnumerateDeviceDescriptorsCallback(descriptors);
+}
+
+}  // namespace video_capture