config: generate graphics-initialized event in the frontend

src/it/tests/t0013_graphics_initialized.rs

@@ -0,0 +1,18 @@
+use {
+    crate::it::{test_error::TestResult, testrun::TestRun},
+    std::rc::Rc,
+};
+
+testcase!();
+
+async fn test(run: Rc<TestRun>) -> TestResult {
+    run.sync().await;
+
+    tassert!(!run.cfg.graphics_initialized.get());
+
+    run.backend.install_render_context()?;
+
+    tassert!(run.cfg.graphics_initialized.get());
+
+    Ok(())
+}