Output DeviceName from various windows ScreenCapturer related implementations

webrtc/modules/desktop_capture/win/screen_capture_utils_unittest.cc

+/*
+ *  Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/modules/desktop_capture/win/screen_capture_utils.h"
+
+#include <vector>
+#include <string>
+
+#include "webrtc/modules/desktop_capture/desktop_capturer.h"
+#include "webrtc/test/gtest.h"
+
+namespace webrtc {
+
+TEST(ScreenCaptureUtilsTest, GetScreenList) {
+  DesktopCapturer::SourceList screens;
+  std::vector<std::string> device_names;
+
+  GetScreenList(&screens);
+  screens.clear();
+  GetScreenList(&screens, &device_names);
+
+  ASSERT_EQ(screens.size(), device_names.size());
+}
+
+}  // namespace webrtc