Clean up gating and order of getting display/glcontext from glutin

This patch simply simplify the OS gating for getting display and gl
context from glutin since it is only used for a linux, mac and not
UWP-based windows.

Also, in linux tries to fetch the wayland display and don't rely
on EGLDisplay because it might bring problems in servo/media.
Nonetheless it is required to compile render-unix in servo-media
with feature 'gl-wayland'

ports/glutin/context.rs

@@ -85,13 +85,7 @@ impl GlContext {
     pub fn raw_context(&self) -> RawContext {
         match self {
             GlContext::Current(c) => {
-                #[cfg(any(
+                #[cfg(target_os = "linux")]
-                    target_os = "linux",
-                    target_os = "dragonfly",
-                    target_os = "freebsd",
-                    target_os = "netbsd",
-                    target_os = "openbsd",
-                ))]
                 {
                     use glutin::os::unix::RawHandle;
 
@@ -114,23 +108,14 @@ impl GlContext {
                     }
                 }
 
-                #[cfg(target_os = "android")]
+                // @TODO(victor): https://github.com/rust-windowing/glutin/pull/1221
-                {
+                //                https://github.com/servo/media/pull/315
-                    let raw_handle = unsafe { c.raw_handle() };
-                    return RawContext::Egl(raw_handle as usize);
-                }
-
                 #[cfg(target_os = "macos")]
-                return unimplemented!(); // @TODO(victor): RawContext::Cocoa in servo-media
+                return unimplemented!();
 
                 #[cfg(not(any(
                     target_os = "linux",
-                    target_os = "dragonfly",
-                    target_os = "freebsd",
-                    target_os = "netbsd",
-                    target_os = "openbsd",
                     target_os = "windows",
-                    target_os = "android",
                     target_os = "macos",
                 )))]
                 unimplemented!()

ports/glutin/headed_window.rs

@@ -14,6 +14,8 @@ use gleam::gl;
 use glutin::dpi::{LogicalPosition, LogicalSize, PhysicalSize};
 #[cfg(target_os = "macos")]
 use glutin::os::macos::{ActivationPolicy, WindowBuilderExt};
+#[cfg(target_os = "linux")]
+use glutin::os::unix::WindowExt;
 use glutin::Api;
 #[cfg(any(target_os = "linux", target_os = "windows"))]
 use glutin::Icon;
@@ -577,10 +579,10 @@ impl WindowMethods for Window {
 
     fn get_gl_context(&self) -> PlayerGLContext {
         if pref!(media.glvideo.enabled) {
-            self.gl_context.borrow().raw_context()
+            return self.gl_context.borrow().raw_context();
-        } else {
-            PlayerGLContext::Unknown
         }
+
+        return PlayerGLContext::Unknown;
     }
 
     fn get_native_display(&self) -> NativeDisplay {
@@ -588,63 +590,25 @@ impl WindowMethods for Window {
             return NativeDisplay::Unknown;
         }
 
-        #[cfg(any(
+        #[cfg(target_os = "linux")]
-            target_os = "linux",
+        {
-            target_os = "dragonfly",
+            if let Some(display) = self.gl_context.borrow().window().get_wayland_display() {
-            target_os = "freebsd",
+                return NativeDisplay::Wayland(display as usize);
-            target_os = "netbsd",
+            } else if let Some(display) =
-            target_os = "openbsd",
+                self.gl_context.borrow().window().get_xlib_display()
-            target_os = "windows",
+            {
-            target_os = "android",
+                return NativeDisplay::X11(display as usize);
-        ))]
-        let native_display = {
-            if let Some(display) = self.gl_context.borrow().egl_display() {
-                NativeDisplay::Egl(display as usize)
-            } else {
-                #[cfg(any(
-                    target_os = "linux",
-                    target_os = "dragonfly",
-                    target_os = "freebsd",
-                    target_os = "netbsd",
-                    target_os = "openbsd",
-                ))]
-                {
-                    use glutin::os::unix::WindowExt;
-
-                    if let Some(display) = self.gl_context.borrow().window().get_wayland_display() {
-                        NativeDisplay::Wayland(display as usize)
-                    } else if let Some(display) =
-                        self.gl_context.borrow().window().get_xlib_display()
-                    {
-                        NativeDisplay::X11(display as usize)
-                    } else {
-                        NativeDisplay::Unknown
-                    }
-                }
-
-                #[cfg(not(any(
-                    target_os = "linux",
-                    target_os = "dragonfly",
-                    target_os = "freebsd",
-                    target_os = "netbsd",
-                    target_os = "openbsd",
-                )))]
-                NativeDisplay::Unknown
             }
-        };
+        }
 
-        #[cfg(not(any(
+        #[cfg(any(target_os = "linux", target_os = "windows"))]
-            target_os = "linux",
+        {
-            target_os = "dragonfly",
+            if let Some(display) = self.gl_context.borrow().egl_display() {
-            target_os = "freebsd",
+                return NativeDisplay::Egl(display as usize);
-            target_os = "netbsd",
+            }
-            target_os = "openbsd",
+        }
-            target_os = "windows",
-            target_os = "android",
-        )))]
-        let native_display = NativeDisplay::Unknown;
 
-        native_display
+        NativeDisplay::Unknown
     }
 
     fn get_gl_api(&self) -> GlApi {