Mac a11y: Add RoleDescription and Value attributes to accessibility information.

ui/gfx/mac/coordinate_conversion.mm

Index: ui/gfx/mac/coordinate_conversion.mm
diff --git a/ui/gfx/mac/coordinate_conversion.mm b/ui/gfx/mac/coordinate_conversion.mm
index b31ce9e1451b2d33a6f70f287d5fdf7d876eaff5..9932842cff4fc87b8995f01420bcdb0e0e0dd75d 100644
--- a/ui/gfx/mac/coordinate_conversion.mm
+++ b/ui/gfx/mac/coordinate_conversion.mm
@@ -8,6 +8,7 @@
 
 #include "ui/gfx/geometry/point.h"
 #include "ui/gfx/geometry/rect.h"
+#include "ui/gfx/geometry/size.h"
 
 namespace gfx {
 
@@ -34,6 +35,14 @@ Rect ScreenRectFromNSRect(const NSRect& rect) {
               rect.size.width, rect.size.height);
 }
 
+NSSize ScreenSizeToNSSize(const Size& size) {
+  return NSMakeSize(size.width(), size.height());
+}
+
+Size ScreenSizeFromNSSize(const NSSize& size) {
+  return Size(size.width, size.height);
+}
+
 NSPoint ScreenPointToNSPoint(const Point& point) {
   return NSMakePoint(point.x(), PrimaryDisplayHeight() - point.y());
 }