Doesn't build on darwin and probably other platforms.
GsWidget.H:26:3: error: 'Atom' does not name a type; did you mean 'tm'?
Atom atoms[5];
^~~~
tm
GsWidget.cxx: In member function 'void GsWidget::setProps()':
GsWidget.cxx:47:2: error: 'atoms' was not declared in this scope
atoms[0] = XInternAtom(fl_display,"GHOSTVIEW" , false);
^~~~~
/cc ZHF #45961
Fixes a critical issue with macOS
[NEWS](https://bitbucket.org/mituharu/emacs-mac/raw/master/NEWS-mac)
* emacs-26.1-mac-7.2 (2018-09-09)
** Fixed bugs
*** Buffer contents are not displayed on macOS 10.14.
This is mainly because now NSViews are backed by Core Animation Layer
(layer-backed) by default and non-deferred drawing into views no
longer works. Instead of switching to deferred drawing (i.e., draw
only inside -[NSView drawRect:]), we draw into our own backing bitmap
in a non-deferred way as before, and update the view contents with the
resulting image via -[NSView updateLayer]. This "application-side
double buffering" is also available on OS X 10.8 - macOS 10.13 if you
set the frame parameter `inhibit-double-buffering' to nil when
creating a frame. Just like on macOS 10.14, such a frame does not do
LCD smoothing.
*** Screenshot grabbed via Services is displayed in wrong size when we
have display mirroring between Retina and non-Retina displays.
*** Cursor movement just after frame resize sometimes leaves garbage.
*** Crash by the Fall_threads call from the GUI thread at the select
emulation when there are multiple Lisp threads.
*** Info title has ASCII underline unlike other window systems.
*** Vertical scroll bar is created as horizontal if frame font height
is short.
** Improvements
*** macOS 10.14 adds property :appearance to (mac-application-state).
The value may be "NSAppearanceNameAqua" or "NSAppearanceNameDarkAqua".
*** Add new color format "mac:COLOR-LIST-NAME:COLOR-NAME" and
"mac:COLOR-NAME" (shorthand for "mac:System:COLOR-NAME"). The actual
color may be different depending on the global appearance setting on
macOS 10.14. For example, "mac:textColor" is black on the Light Mode
but is white on the Dark Mode.
*** Default frame colors respect appearance setting on macOS 10.14.
Now the default frame foreground/background color is
"mac:textColor"/"mac:textBackgroundColor", respectively. Changes of
the system setting of the global appearance are dynamically reflected.
*** New function `mac-color-list-alist' to get the available
combinations of COLOR-LIST-NAMEs and COLOR-NAMEs. Note that this
value is dependent on user environment and OS version. Also, some
combinations may represent image patterns rather than colors. For the
former cases, `(color-values "mac:COLOR-LIST-NAME:COLOR-NAME")'
returns nil.
