api: make OwnedDisplayHandle wrap an opaque type

This will help in case we want to linger the event loop during drop
to prevent use after free in the consumers code.

src/platform_impl/web/event_loop/mod.rs

@@ -10,7 +10,7 @@ pub(crate) mod runner;
 mod state;
 mod window_target;
 
-pub(crate) use window_target::{ActiveEventLoop, OwnedDisplayHandle};
+pub(crate) use window_target::ActiveEventLoop;
 
 pub struct EventLoop {
     elw: ActiveEventLoop,

src/platform_impl/web/event_loop/window_target.rs

@@ -14,7 +14,7 @@ use crate::error::{NotSupportedError, RequestError};
 use crate::event::{ElementState, Event, KeyEvent, TouchPhase, WindowEvent};
 use crate::event_loop::{
     ActiveEventLoop as RootActiveEventLoop, ControlFlow, DeviceEvents,
-    EventLoopProxy as RootEventLoopProxy, OwnedDisplayHandle as RootOwnedDisplayHandle,
+    EventLoopProxy as RootEventLoopProxy, OwnedDisplayHandle as CoreOwnedDisplayHandle,
 };
 use crate::keyboard::ModifiersState;
 use crate::monitor::MonitorHandle as RootMonitorHandle;
@@ -547,8 +547,8 @@ impl RootActiveEventLoop for ActiveEventLoop {
         self.runner.exiting()
     }
 
-    fn owned_display_handle(&self) -> RootOwnedDisplayHandle {
-        RootOwnedDisplayHandle { platform: OwnedDisplayHandle }
+    fn owned_display_handle(&self) -> CoreOwnedDisplayHandle {
+        CoreOwnedDisplayHandle::new(Arc::new(OwnedDisplayHandle))
     }
 
     fn rwh_06_handle(&self) -> &dyn rwh_06::HasDisplayHandle {
@@ -563,14 +563,12 @@ impl rwh_06::HasDisplayHandle for ActiveEventLoop {
     }
 }
 
-#[derive(Clone, PartialEq, Eq)]
+#[derive(Clone)]
 pub(crate) struct OwnedDisplayHandle;
 
-impl OwnedDisplayHandle {
-    #[inline]
-    pub fn raw_display_handle_rwh_06(
-        &self,
-    ) -> Result<rwh_06::RawDisplayHandle, rwh_06::HandleError> {
-        Ok(rwh_06::WebDisplayHandle::new().into())
+impl rwh_06::HasDisplayHandle for OwnedDisplayHandle {
+    fn display_handle(&self) -> Result<rwh_06::DisplayHandle<'_>, rwh_06::HandleError> {
+        let raw = rwh_06::RawDisplayHandle::Web(rwh_06::WebDisplayHandle::new());
+        unsafe { Ok(rwh_06::DisplayHandle::borrow_raw(raw)) }
     }
 }

src/platform_impl/web/mod.rs

@@ -38,7 +38,7 @@ pub(crate) use cursor::{
 };
 
 pub(crate) use self::event_loop::{
-    ActiveEventLoop, EventLoop, OwnedDisplayHandle, PlatformSpecificEventLoopAttributes,
+    ActiveEventLoop, EventLoop, PlatformSpecificEventLoopAttributes,
 };
 pub(crate) use self::keyboard::KeyEventExtra;
 pub(crate) use self::monitor::{