[WebRTC] Implement Windows ScreenDrawer to test ScreenCapturer*

webrtc/modules/desktop_capture/screen_drawer_win.h

+/*
+ *  Copyright (c) 2016 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.
+ */
+
+#ifndef MODULES_DESKTOP_CAPTURE_SCREEN_DRAWER_WIN_H_
+#define MODULES_DESKTOP_CAPTURE_SCREEN_DRAWER_WIN_H_
+
+#include "webrtc/modules/desktop_capture/screen_drawer.h"
+
+#include <windows.h>
+
+namespace webrtc {
+
+// A ScreenDrawer implementation for Windows.
+class ScreenDrawerWin : public ScreenDrawer {
+ public:
+  ScreenDrawerWin();
+  ~ScreenDrawerWin() override;
+
+  DesktopRect DrawableRegion() override;
+  void DrawRectangle(DesktopRect rect, uint32_t rgba) override;
+
+ private:
+  const DesktopRect rect_;
+  HWND window_;
+  HDC hdc_;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_DESKTOP_CAPTURE_SCREEN_DRAWER_WIN_H_