Wrap ScreenCapturer with ScreenCapturerDifferWrapper

webrtc/modules/desktop_capture/desktop_capture_options.h

Index: webrtc/modules/desktop_capture/desktop_capture_options.h
diff --git a/webrtc/modules/desktop_capture/desktop_capture_options.h b/webrtc/modules/desktop_capture/desktop_capture_options.h
index 2aa3e5197c0b3672d08a9e9dbaf574e116d35906..c2ac1d632ee0624b0d1b17724f7a11b62f1a2a27 100644
--- a/webrtc/modules/desktop_capture/desktop_capture_options.h
+++ b/webrtc/modules/desktop_capture/desktop_capture_options.h
@@ -72,6 +72,14 @@ class DesktopCaptureOptions {
     disable_effects_ = disable_effects;
   }
 
+  // Flag that should be set if the consumer uses updated_region() and the
+  // capturer should try to provide correct updated_region() for the frames it
+  // generates (e.g. by comparing each frame with the previous one).

[Sergey Ulanov, 2016/09/15 23:51:35]

Currently this flag is ignored in WindowCapturer implementations. Please mention
it here and add a TODO to fix it.

[Hzj_jie, 2016/09/16 00:31:18]

Done.

+  bool detect_updated_region() const { return detect_updated_region_; }
+  void set_detect_updated_region(bool detect_updated_region) {
+    detect_updated_region_ = detect_updated_region;
+  }
+
 #if defined(WEBRTC_WIN)
   bool allow_use_magnification_api() const {
     return allow_use_magnification_api_;
@@ -110,6 +118,7 @@ class DesktopCaptureOptions {
   bool use_update_notifications_ = true;
 #endif
   bool disable_effects_ = true;
+  bool detect_updated_region_ = false;
 };
 
 }  // namespace webrtc