Remove WINIT_LINK_COLORSYNC (no longer needed)

Since rust-windowing#2078 we link to `ApplicationServices`, which contains the `CGDisplayCreateUUIDFromDisplayID` symbol in all versions.

CHANGELOG.md

@@ -1,5 +1,6 @@
 # Unreleased
 
+- Remove no longer needed `WINIT_LINK_COLORSYNC` environment variable.
 - Fix linking to the `ColorSync` framework on macOS 10.7, and in newer Rust versions.
 - On Web, implement cursor grabbing through the pointer lock API.
 - On X11, add mappings for numpad comma, numpad enter, numlock and pause.

README.md

@@ -118,13 +118,3 @@ fn main() {
 ```
 
 And run the application with `cargo apk run --example request_redraw_threaded`
-
-#### MacOS
-
-To ensure compatibility with older MacOS systems, winit links to
-CGDisplayCreateUUIDFromDisplayID through the CoreGraphics framework.
-However, under certain setups this function is only available to be linked
-through the newer ColorSync framework. So, winit provides the
-`WINIT_LINK_COLORSYNC` environment variable which can be set to `1` or `true`
-while compiling to enable linking via ColorSync.
-

src/platform_impl/macos/ffi.rs

@@ -170,16 +170,7 @@ pub type CGDisplayModeRef = *mut c_void;
 // directly. Fortunately, it has always been available as a subframework of
 // `ApplicationServices`, see:
 // https://developer.apple.com/library/archive/documentation/MacOSX/Conceptual/OSX_Technology_Overview/SystemFrameworks/SystemFrameworks.html#//apple_ref/doc/uid/TP40001067-CH210-BBCFFIEG
-//
-// TODO: Remove the WINIT_LINK_COLORSYNC hack, it is probably not needed.
-#[cfg_attr(
-    not(use_colorsync_cgdisplaycreateuuidfromdisplayid),
-    link(name = "ApplicationServices", kind = "framework")
-)]
-#[cfg_attr(
-    use_colorsync_cgdisplaycreateuuidfromdisplayid,
-    link(name = "ColorSync", kind = "framework")
-)]
+#[link(name = "ApplicationServices", kind = "framework")]
 extern "C" {
     pub fn CGDisplayCreateUUIDFromDisplayID(display: CGDirectDisplayID) -> CFUUIDRef;
 }