DesktopRect::UnionWith() to extend current rect to cover the input rect

webrtc/modules/desktop_capture/desktop_geometry.h

Index: webrtc/modules/desktop_capture/desktop_geometry.h
diff --git a/webrtc/modules/desktop_capture/desktop_geometry.h b/webrtc/modules/desktop_capture/desktop_geometry.h
index 8e9b9183a82e9f781840da14ae977ecd442ba09e..a14ad7832eacadd7189650fa790ce0ad47526af5 100644
--- a/webrtc/modules/desktop_capture/desktop_geometry.h
+++ b/webrtc/modules/desktop_capture/desktop_geometry.h
@@ -124,6 +124,11 @@ class DesktopRect {
   // Finds intersection with |rect|.
   void IntersectWith(const DesktopRect& rect);
 
+  // Finds the minimum area to cover both |this| and |rect|. If |this| is empty,

[Sergey Ulanov, 2017/05/16 19:53:00]

It's not clear from this comment that the result is stored in the same object.
Maybe reword the first sentence as "Extends the rectangle to cover |rect|."

[Hzj_jie, 2017/05/16 23:04:18]

Done.

+  // replaces |this| with |rect|; if |rect| is empty, this function takes no
+  // effect.
+  void UnionWith(const DesktopRect& rect);
+
   // Adds (dx, dy) to the position of the rectangle.
   void Translate(int32_t dx, int32_t dy);
   void Translate(DesktopVector d) { Translate(d.x(), d.y()); };