Rename Window::set_inner_size to Window::request_inner_size

Some systems could resize the window immediately and we'd rather
inform the users right away if that was the case, so they could
create e.g. EGLSurface without waiting for resize, which is really
important for Wayland.

Fixes #2868.

src/platform_impl/ios/window.rs

@@ -139,8 +139,8 @@ impl Inner {
         }
     }
 
-    pub fn set_inner_size(&self, _size: Size) {
-        warn!("not clear what `Window::set_inner_size` means on iOS");
+    pub fn request_inner_size(&self, _size: Size) -> Option<PhysicalSize<u32>> {
+        Some(self.inner_size())
     }
 
     pub fn set_min_inner_size(&self, _dimensions: Option<Size>) {