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

ui/gfx/mac/coordinate_conversion.h

Index: ui/gfx/mac/coordinate_conversion.h
diff --git a/ui/gfx/mac/coordinate_conversion.h b/ui/gfx/mac/coordinate_conversion.h
index 3b75485357b72d3ad6aff7a1e220000bebd30201..6ced20b261aa56347ef73eb03dfb6fe6ea59700e 100644
--- a/ui/gfx/mac/coordinate_conversion.h
+++ b/ui/gfx/mac/coordinate_conversion.h
@@ -13,15 +13,22 @@ namespace gfx {
 
 class Point;
 class Rect;
+class Size;
 
 // Convert a gfx::Rect specified with the origin at the top left of the primary
-// display into AppKit secreen coordinates (origin at the bottom left).
+// display into AppKit screen coordinates (origin at the bottom left).
 GFX_EXPORT NSRect ScreenRectToNSRect(const Rect& rect);
 
 // Convert an AppKit NSRect with origin in the bottom left of the primary
 // display into a gfx::Rect with origin at the top left of the primary display.
 GFX_EXPORT Rect ScreenRectFromNSRect(const NSRect& point);
 
+// Convert a gfx::Size specified in pixels display into AppKit screen sizes.
+GFX_EXPORT NSSize ScreenSizeToNSSize(const Size& size);

[tapted, 2016/06/06 04:09:51]

Something like `NSSize ns_size = size.ToCGSize()` should work -- CGSize and
NSSize are sorta the same, and I think the compiler just allows this to happen.

Similarly, I think `gfx::Size gfx_size(NSMakeSize(x, y));` Just Works.

[Patti Lor, 2016/06/10 01:36:10]

Done.

+
+// Convert an AppKit NSSize into a gfx::Size.
+GFX_EXPORT Size ScreenSizeFromNSSize(const NSSize& size);
+
 // Convert a gfx::Point specified with the origin at the top left of the primary
 // display into AppKit screen coordinates (origin at the bottom left).
 GFX_EXPORT NSPoint ScreenPointToNSPoint(const Point& point);