Wrap ScreenCapturer with ScreenCapturerDifferWrapper

webrtc/modules/desktop_capture/screen_capturer_unittest.cc

 /*
  *  Copyright (c) 2013 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.
  */
 
@@ skipping 111 matching lines @@
         TestCaptureOneFrame(capturers, drawer.get(), rect, color);
       }
     }
   }
 
   void TestCaptureUpdatedRegion() {
     TestCaptureUpdatedRegion({capturer_.get()});
   }
 
 #if defined(WEBRTC_WIN)
+  // Enable allow_directx_capturer in DesktopCaptureOptions, but let
+  // ScreenCapturer::Create to decide whether a DirectX capturer should be used.
+  void MaybeCreateDirectxCapturer() {
+    DesktopCaptureOptions options(DesktopCaptureOptions::CreateDefault());
+    options.set_allow_directx_capturer(true);
+    capturer_.reset(ScreenCapturer::Create(options));
+  }
+
   bool CreateDirectxCapturer() {
     if (!ScreenCapturerWinDirectx::IsSupported()) {
       LOG(LS_WARNING) << "Directx capturer is not supported";
       return false;
     }
 
-    DesktopCaptureOptions options(DesktopCaptureOptions::CreateDefault());
-    options.set_allow_directx_capturer(true);
-    capturer_.reset(ScreenCapturer::Create(options));
+    MaybeCreateDirectxCapturer();
     return true;
   }
 
   void CreateMagnifierCapturer() {
     DesktopCaptureOptions options(DesktopCaptureOptions::CreateDefault());
     options.set_allow_use_magnification_api(true);
     capturer_.reset(ScreenCapturer::Create(options));
   }
 #endif  // defined(WEBRTC_WIN)
 
@@ skipping 214 matching lines @@
   TestCaptureUpdatedRegion({capturer_.get(), capturer2.get()});
 }
 
 TEST_F(ScreenCapturerTest, TwoMagnifierCapturers) {
   CreateMagnifierCapturer();
   std::unique_ptr<ScreenCapturer> capturer2 = std::move(capturer_);
   CreateMagnifierCapturer();
   TestCaptureUpdatedRegion({capturer_.get(), capturer2.get()});
 }
 
+TEST_F(ScreenCapturerTest, MaybeCaptureUpdatedRegionWithDirectxCapturer) {
+  // Even DirectX capturer is not supported in current system, we should be able
+  // to select a usable capturer.
+  MaybeCreateDirectxCapturer();
+  TestCaptureUpdatedRegion();
+}
+
 #endif  // defined(WEBRTC_WIN)
 
 }  // namespace webrtc