Add autofocus mode.

tests/native_browser.py

@@ -12,6 +12,7 @@ from native_test_session import run_private_session
 
 
 BROWSER_PROOFS = {
+    "structural-focus": ("./internal/app", "^TestNativeBrowserStructuralFocus$", 45, 50),
     "disabled-fields": ("./internal/app", "^TestNativeBrowserDisabledFieldsRemainReadable$", 40, 70, "browser-disabled-fields.html"),
     "live-atomic": ("./internal/atspi", "^TestNativeBrowserAtomicLiveRegion$", 30, 35, "browser-live.html"),
     "replaced-feed": ("./internal/atspi", "^TestNativeBrowserMissingFeedRefreshesWholeBranch$", 30, 35, "browser-replaced-feed.html"),