Remove the requirement of D3D_FEATURE_LEVEL_11_0, but export the D3D_FEATURE_LEVEL through APIs

webrtc/modules/desktop_capture/win/dxgi_duplicator_controller.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 WEBRTC_MODULES_DESKTOP_CAPTURE_WIN_DXGI_DUPLICATOR_CONTROLLER_H_
 #define WEBRTC_MODULES_DESKTOP_CAPTURE_WIN_DXGI_DUPLICATOR_CONTROLLER_H_
 
+#include <D3DCommon.h>
+
 #include <memory>
 #include <vector>
 
 #include "webrtc/base/criticalsection.h"
 #include "webrtc/modules/desktop_capture/desktop_geometry.h"
 #include "webrtc/modules/desktop_capture/desktop_region.h"
 #include "webrtc/modules/desktop_capture/shared_desktop_frame.h"
 #include "webrtc/modules/desktop_capture/win/d3d_device.h"
 #include "webrtc/modules/desktop_capture/win/dxgi_adapter_duplicator.h"
 
@@ skipping 26 matching lines @@
 
     // A Context will have an exactly same |identity_| as
     // DxgiDuplicatorController, to ensure it has been correctly setted up after
     // each DxgiDuplicatorController::Initialize().
     int identity_ = 0;
 
     // Child DxgiAdapterDuplicator::Context belongs to this Context.
     std::vector<DxgiAdapterDuplicator::Context> contexts_;
   };
 
+  // A collection of D3d information we are interested on, which may impact
+  // capturer performance or reliability.
+  struct D3dInfo {
+    // Each video adapter has its own D3D_FEATURE_LEVEL, so this structure
+    // contains the minimum and maximium D3D_FEATURE_LEVELs current system
+    // supports.
+    // Both fields can be 0, which is the default value to indicate no valid
+    // D3D_FEATURE_LEVEL has been retrieved from underlying OS APIs.
+    D3D_FEATURE_LEVEL min_feature_level;
+    D3D_FEATURE_LEVEL max_feature_level;
+
+    // TODO(zijiehe): Add more fields, such as manufacturer name, mode, driver
+    // version.
+  };
+
   // Returns the singleton instance of DxgiDuplicatorController.
   static DxgiDuplicatorController* Instance();
 
   // Destructs current instance. We need to make sure COM components and their
   // containers are destructed in correct order.
   ~DxgiDuplicatorController();
 
+  // All the following functions implicitly call Initialize() function is
+  // current instance has not been initialized.
+
   // Detects whether the system supports DXGI based capturer.
   bool IsSupported();
 
+  // Returns a copy of D3dInfo composed by last Initialize() function call.
+  bool RetrieveD3dInfo(D3dInfo* info);
+
   // Captures current screen and writes into target. Since we are using double
   // buffering, |last_frame|.updated_region() is used to represent the not
   // updated regions in current |target| frame, which should also be copied this
   // time.
   // TODO(zijiehe): Windows cannot guarantee the frames returned by each
   // IDXGIOutputDuplication are synchronized. But we are using a totally
   // different threading model than the way Windows suggested, it's hard to
   // synchronize them manually. We should find a way to do it.
   bool Duplicate(Context* context, SharedDesktopFrame* target);
 
@@ skipping 66 matching lines @@
 
   // This lock must be locked whenever accessing any of the following objects.
   rtc::CriticalSection lock_;
 
   // A self-incremented integer to compare with the one in Context, to
   // ensure a Context has been initialized after DxgiDuplicatorController.
   int identity_ = 0;
   DesktopRect desktop_rect_;
   DesktopVector dpi_;
   std::vector<DxgiAdapterDuplicator> duplicators_;
+  D3dInfo d3d_info_;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_DESKTOP_CAPTURE_WIN_DXGI_DUPLICATOR_CONTROLLER_H_