Revert of Remove all reference to carbon api

webrtc/modules/desktop_capture/mac/desktop_configuration.h

Index: webrtc/modules/desktop_capture/mac/desktop_configuration.h
diff --git a/webrtc/modules/desktop_capture/mac/desktop_configuration.h b/webrtc/modules/desktop_capture/mac/desktop_configuration.h
index 241c5b9db2bca086471604c5164a7676668593a9..bb2339bb0f110f0c3c1e9451b641882aab70202f 100644
--- a/webrtc/modules/desktop_capture/mac/desktop_configuration.h
+++ b/webrtc/modules/desktop_capture/mac/desktop_configuration.h
@@ -12,6 +12,7 @@
 #define WEBRTC_MODULES_DESKTOP_CAPTURE_MAC_DESKTOP_CONFIGURATION_H_
 
 #include <ApplicationServices/ApplicationServices.h>
+#include <Carbon/Carbon.h>
 #include <vector>
 
 #include "webrtc/typedefs.h"
@@ -48,7 +49,7 @@
 
   // Returns the desktop & display configurations in Cocoa-style "bottom-up"
   // (the origin is the bottom-left of the primary monitor, and coordinates
-  // increase as you move up the screen).
+  // increase as you move up the screen) or Carbon-style "top-down" coordinates.
   static MacDesktopConfiguration GetCurrent(Origin origin);
 
   // Returns true if the given desktop configuration equals this one.