Add CreateWindowCapturer() and CreateScreenCapturer() in DesktopCapturer

webrtc/modules/desktop_capture/screen_capturer_mac.mm

Index: webrtc/modules/desktop_capture/screen_capturer_mac.mm
diff --git a/webrtc/modules/desktop_capture/screen_capturer_mac.mm b/webrtc/modules/desktop_capture/screen_capturer_mac.mm
index 49910d600f96da1ea62c8125f9fd4a91dac0a7b9..f8d8eb7ce5fa22b38bbc5868d173bbf274e86f56 100644
--- a/webrtc/modules/desktop_capture/screen_capturer_mac.mm
+++ b/webrtc/modules/desktop_capture/screen_capturer_mac.mm
@@ -1037,4 +1037,19 @@ ScreenCapturer* ScreenCapturer::Create(const DesktopCaptureOptions& options) {
   return capturer.release();
 }
 
+// static
+std::unique_ptr<DesktopCapturer> DesktopCapturer::CreateRawScreenCapturer(
+    const DesktopCaptureOptions& options) {
+  if (!options.configuration_monitor())
+    return nullptr;
+
+  std::unique_ptr<ScreenCapturer> capturer(
+      new ScreenCapturerMac(options.configuration_monitor()));
+  if (!static_cast<ScreenCapturerMac*>(capturer.get())->Init()) {
+    return nullptr;
+  }
+
+  return capturer;
+}
+
 }  // namespace webrtc