DirectX based screen capturer logic

webrtc/modules/desktop_capture/desktop_geometry.cc

Index: webrtc/modules/desktop_capture/desktop_geometry.cc
diff --git a/webrtc/modules/desktop_capture/desktop_geometry.cc b/webrtc/modules/desktop_capture/desktop_geometry.cc
index 1ff7c683c79828a0d8c4e5f9c4c4cb23fd365243..0881c6f0175eb50798f0958630a8c657bcd36592 100644
--- a/webrtc/modules/desktop_capture/desktop_geometry.cc
+++ b/webrtc/modules/desktop_capture/desktop_geometry.cc
@@ -44,5 +44,18 @@ void DesktopRect::Translate(int32_t dx, int32_t dy) {
   bottom_ += dy;
 }
 
+DesktopRect DesktopRect::Expand(uint32_t padding,
+                                const DesktopSize& size) const {
+  int32_t l = left() - padding;
+  int32_t t = top() - padding;
+  int32_t r = right() + padding;
+  int32_t b = bottom() + padding;
+  if (l < 0) l = 0;
+  if (t < 0) t = 0;
+  if (r > size.width()) r = size.width();
+  if (b > size.height()) b = size.height();
+  return DesktopRect(l, t, r, b);
+}
+
 }  // namespace webrtc