No template-for
This is the placeholder document.
The browser ignored <template for>, so the
<?start> / <?end> ranges were
never replaced. You are reading the fallback page that shipped in
those ranges.
A browser with Declarative Partial Updates would have thrown this page away and filled in a different title, styles, and article from the templates at the bottom of the file.
chrome://flags/#enable-experimental-web-platform-features
is enabled. This file does not load the polyfill, so support has to
be native.