[Chromoting] Improve DirectX capturer to support multiple outputs

webrtc/modules/desktop_capture/desktop_capturer.h

 /*
  *  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.
  */
 
 #ifndef WEBRTC_MODULES_DESKTOP_CAPTURE_DESKTOP_CAPTURER_H_
 #define WEBRTC_MODULES_DESKTOP_CAPTURE_DESKTOP_CAPTURER_H_
 
 #include <stddef.h>
 
 #include <memory>
 
+#include "webrtc/base/checks.h"
 #include "webrtc/modules/desktop_capture/desktop_frame.h"
 #include "webrtc/modules/desktop_capture/desktop_capture_types.h"
 #include "webrtc/modules/desktop_capture/shared_memory.h"
 
 namespace webrtc {
 
 class DesktopFrame;
 
 // Abstract interface for screen and window capturers.
 class DesktopCapturer {
@@ skipping 14 matching lines @@
   };
 
   // Interface that must be implemented by the DesktopCapturer consumers.
   class Callback {
    public:
     // Called after a frame has been captured. |frame| is not nullptr if and
     // only if |result| is SUCCESS.
     virtual void OnCaptureResult(Result result,
                                  std::unique_ptr<DesktopFrame> frame) = 0;
 
+    // A shortcut to return a temporary error.
+    void OnTemporaryError() {

[Sergey Ulanov, 2016/07/08 22:36:53]

Please don't add these methods here. Callback is an abstract interface and all
methods should be pure virtual. You can add these functions outside of this
interface if you think they may be useful.

[Hzj_jie, 2016/07/11 00:54:59]

Done.

+      OnCaptureResult(Result::ERROR_TEMPORARY, nullptr);
+    }
+
+    // A shortcut to return a permanent error.
+    void OnPermanentError() {
+      OnCaptureResult(Result::ERROR_PERMANENT, nullptr);
+    }
+
+    // A shortcut to return a capture result.
+    void OnCaptureSucceeded(std::unique_ptr<DesktopFrame> frame) {
+      RTC_DCHECK(frame);
+      OnCaptureResult(Result::SUCCESS, std::move(frame));
+    }
+
    protected:
     virtual ~Callback() {}
   };
 
   virtual ~DesktopCapturer() {}
 
   // Called at the beginning of a capturing session. |callback| must remain
   // valid until capturer is destroyed.
   virtual void Start(Callback* callback) = 0;
 
@@ skipping 15 matching lines @@
   // Sets the window to be excluded from the captured image in the future
   // Capture calls. Used to exclude the screenshare notification window for
   // screen capturing.
   virtual void SetExcludedWindow(WindowId window) {}
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_DESKTOP_CAPTURE_DESKTOP_CAPTURER_H_