MacViews: Implement capture using NSEvent local+global monitors

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 b2c41a455d6c96c4aa18e2928937c1c93f3cdb45..ed47d06845fd8e71372be4560d146b1870eed897 100644
--- a/ui/gfx/mac/coordinate_conversion.mm
+++ b/ui/gfx/mac/coordinate_conversion.mm
@@ -7,6 +7,7 @@
 #import <Cocoa/Cocoa.h>
 
 #include "ui/gfx/geometry/rect.h"
+#include "ui/gfx/geometry/point.h"
 
 namespace gfx {
 
@@ -34,4 +35,12 @@ gfx::Rect ScreenRectFromNSRect(const NSRect& rect) {
                    rect.size.height);
 }
 
+NSPoint ScreenPointToNSPoint(const gfx::Point& point) {
+  return NSMakePoint(point.x(), PrimaryDisplayHeight() - point.y());
+}
+
+gfx::Point ScreenPointFromNSPoint(const NSPoint& point) {
+  return gfx::Point(point.x, PrimaryDisplayHeight() - point.y);
+}
+
 }  // namespace gfx