Revert of Use std::unique_ptr<> to pass frame ownership in DesktopCapturer impls.

webrtc/modules/desktop_capture/window_capturer_unittest.cc

Index: webrtc/modules/desktop_capture/window_capturer_unittest.cc
diff --git a/webrtc/modules/desktop_capture/window_capturer_unittest.cc b/webrtc/modules/desktop_capture/window_capturer_unittest.cc
index d2d326e39f4b0e3cee5a64488bb668fb3f4d6db2..32b8b8f23cbba1a24910f85b274102d42a183a79 100644
--- a/webrtc/modules/desktop_capture/window_capturer_unittest.cc
+++ b/webrtc/modules/desktop_capture/window_capturer_unittest.cc
@@ -31,10 +31,7 @@
   void TearDown() override {}
 
   // DesktopCapturer::Callback interface
-  void OnCaptureResult(DesktopCapturer::Result result,
-                       std::unique_ptr<DesktopFrame> frame) override {
-    frame_ = std::move(frame);
-  }
+  void OnCaptureCompleted(DesktopFrame* frame) override { frame_.reset(frame); }
 
  protected:
   std::unique_ptr<WindowCapturer> capturer_;