Implement requestAnimationFrame for web (#1519)

* Use requestAnimationFrame for polling wasm

* Implement `requestAnimationFrame` for stdweb

Co-authored-by: Ryan G <ryanisaacg@users.noreply.github.com>

src/platform_impl/web/web_sys/timeout.rs

@@ -1,3 +1,5 @@
+use std::cell::Cell;
+use std::rc::Rc;
 use std::time::Duration;
 use wasm_bindgen::closure::Closure;
 use wasm_bindgen::JsCast;
@@ -38,3 +40,48 @@ impl Drop for Timeout {
         window.clear_timeout_with_handle(self.handle);
     }
 }
+
+#[derive(Debug)]
+pub struct AnimationFrameRequest {
+    handle: i32,
+    // track callback state, because `cancelAnimationFrame` is slow
+    fired: Rc<Cell<bool>>,
+    _closure: Closure<dyn FnMut()>,
+}
+
+impl AnimationFrameRequest {
+    pub fn new<F>(mut f: F) -> AnimationFrameRequest
+    where
+        F: 'static + FnMut(),
+    {
+        let window = web_sys::window().expect("Failed to obtain window");
+
+        let fired = Rc::new(Cell::new(false));
+        let c_fired = fired.clone();
+        let closure = Closure::wrap(Box::new(move || {
+            (*c_fired).set(true);
+            f();
+        }) as Box<dyn FnMut()>);
+
+        let handle = window
+            .request_animation_frame(&closure.as_ref().unchecked_ref())
+            .expect("Failed to request animation frame");
+
+        AnimationFrameRequest {
+            handle,
+            fired,
+            _closure: closure,
+        }
+    }
+}
+
+impl Drop for AnimationFrameRequest {
+    fn drop(&mut self) {
+        if !(*self.fired).get() {
+            let window = web_sys::window().expect("Failed to obtain window");
+            window
+                .cancel_animation_frame(self.handle)
+                .expect("Failed to cancel animation frame");
+        }
+    }
+}