Remove asParsedURL on the String prototype

Use a static function on the ParsedURL class instead.

A lot of our tooling is happier linking through to the class method
rather than the prototype thing, and setting things on prototypes is
generally discouraged in JS for a bunch of reasons.

Change-Id: I95cf70ed58e7cca6d4c2bf7633b69199f513d068
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/1958524
Reviewed-by: Tim van der Lippe <tvanderlippe@chromium.org>
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
diff --git a/front_end/audits/AuditsController.js b/front_end/audits/AuditsController.js
index 0ff5c19..cf15210 100644
--- a/front_end/audits/AuditsController.js
+++ b/front_end/audits/AuditsController.js
@@ -69,7 +69,7 @@
       return false;
     }
 
-    const inspectedURL = mainTarget.inspectedURL().asParsedURL();
+    const inspectedURL = Common.ParsedURL.fromString(mainTarget.inspectedURL());
     const inspectedOrigin = inspectedURL && inspectedURL.securityOrigin();
     for (const registration of this._manager.registrations().values()) {
       if (registration.securityOrigin !== inspectedOrigin) {