Remove DesktopRegion parameter in DesktopCapturer::Capture.

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.
  */
 
@@ skipping 48 matching lines @@
   // valid until capturer is destroyed.
   virtual void Start(Callback* callback) = 0;
 
   // Sets SharedMemoryFactory that will be used to create buffers for the
   // captured frames. The factory can be invoked on a thread other than the one
   // where Capture() is called. It will be destroyed on the same thread. Shared
   // memory is currently supported only by some DesktopCapturer implementations.
   virtual void SetSharedMemoryFactory(
       std::unique_ptr<SharedMemoryFactory> shared_memory_factory) {}
 
-  // Captures next frame. |region| specifies region of the capture target that
-  // should be fresh in the resulting frame. The frame may also include fresh
-  // data for areas outside |region|. In that case capturer will include these
-  // areas in updated_region() of the frame. |region| is specified relative to
-  // the top left corner of the capture target. Pending capture operations are
-  // canceled when DesktopCapturer is deleted.
-  virtual void Capture(const DesktopRegion& region) = 0;
+  // This is a legacy interface, consumers should call CaptureFrame() function.
+  virtual void Capture(const DesktopRegion& region) { CaptureFrame(); }
+
+  // Captures next frame, and involve callback provided by Start() function.
+  // Pending capture requests are canceled when DesktopCapturer is deleted.
+  virtual void CaptureFrame() { Capture(DesktopRegion()); }
 
   // 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_