Add reference counter of DxgiDuplicatorController to unload DXGI components

webrtc/modules/desktop_capture/win/screen_capturer_win_directx.h

Index: webrtc/modules/desktop_capture/win/screen_capturer_win_directx.h
diff --git a/webrtc/modules/desktop_capture/win/screen_capturer_win_directx.h b/webrtc/modules/desktop_capture/win/screen_capturer_win_directx.h
index 59f457c5b4dcdd15ec6813983d1540f76b62efd5..5389ee101ccd23725c19844974f138af8aa98138 100644
--- a/webrtc/modules/desktop_capture/win/screen_capturer_win_directx.h
+++ b/webrtc/modules/desktop_capture/win/screen_capturer_win_directx.h
@@ -30,9 +30,19 @@ class ScreenCapturerWinDirectx : public DesktopCapturer {
  public:
   using D3dInfo = DxgiDuplicatorController::D3dInfo;
 
-  // Whether the system supports DirectX based capturing.
+  // Deprecated: use "IsAvailable()" instead.
   static bool IsSupported();
 
+  // Deprecated: use "GetD3dInfo()" instead.
+  static bool RetrieveD3dInfo(D3dInfo* info);
+
+  explicit ScreenCapturerWinDirectx();
+
+  ~ScreenCapturerWinDirectx() override;
+
+  // Whether the system supports DirectX based capturing.
+  bool IsAvailable() const;
+
   // Returns a most recent D3dInfo composed by
   // DxgiDuplicatorController::Initialize() function. This function implicitly
   // calls DxgiDuplicatorController::Initialize() if it has not been
@@ -41,12 +51,9 @@ class ScreenCapturerWinDirectx : public DesktopCapturer {
   // The D3dInfo may change based on hardware configuration even without
   // restarting the hardware and software. Refer to https://goo.gl/OOCppq. So
   // consumers should not cache the result returned by this function.
-  static bool RetrieveD3dInfo(D3dInfo* info);
-
-  explicit ScreenCapturerWinDirectx(const DesktopCaptureOptions& options);
-
-  ~ScreenCapturerWinDirectx() override;
+  bool GetD3dInfo(D3dInfo* info) const;
 
+  // DesktopCapturer implementation.
   void Start(Callback* callback) override;
   void SetSharedMemoryFactory(
       std::unique_ptr<SharedMemoryFactory> shared_memory_factory) override;
@@ -55,6 +62,7 @@ class ScreenCapturerWinDirectx : public DesktopCapturer {
   bool SelectSource(SourceId id) override;
 
  private:
+  const DxgiDuplicatorController::Reference controller_;
   ScreenCaptureFrameQueue<DxgiFrame> frames_;
   std::unique_ptr<SharedMemoryFactory> shared_memory_factory_;
   Callback* callback_ = nullptr;