Backed out changeset 2d3e477fd282

The flush function is removed by Bug 1321417.

gfx/webrender_bindings/src/bindings.rs

@@ -422,9 +422,6 @@ pub extern fn wr_pop_dl_builder(state: &mut WrState, bounds: WrRect, overflow: W
 
 #[no_mangle]
 pub fn wr_composite_window(window: &mut WrWindowState) {
-    window.api.flush();
-    wait_for_flush_notification(&window.flush_notifier_lock);
-
     gl::clear(gl::COLOR_BUFFER_BIT);
     window.renderer.update();
     window.renderer.render(window.size);