core(trace-of-tab): only use navstart of chrome/http documents

lighthouse-core/gather/computed/trace-of-tab.js

@@ -22,11 +22,24 @@ const TracingProcessor = require('../../lib/traces/tracing-processor');
 const LHError = require('../../lib/errors');
 const Sentry = require('../../lib/sentry');
 
+const ACCEPTABLE_NAVIGATION_URL_REGEX = /^(chrome|https?):/;
+
 class TraceOfTab extends ComputedArtifact {
   get name() {
     return 'TraceOfTab';
   }
 
+  /**
+   * Returns true if the event is a navigation start event of a document whose URL seems valid.
+   *
+   * @param {LH.TraceEvent} event
+   */
+  static isNavigationStartOfInterest(event) {
+    return event.name === 'navigationStart' &&
+      (!event.args.data || !event.args.data.documentLoaderURL ||
+        ACCEPTABLE_NAVIGATION_URL_REGEX.test(event.args.data.documentLoaderURL));
+  }
+
   /**
    * @param {LH.TraceEvent[]} traceEvents
    * @param {(e: LH.TraceEvent) => boolean} filter
@@ -79,7 +92,7 @@ class TraceOfTab extends ComputedArtifact {
     const frameEvents = keyEvents.filter(e => e.args.frame === frameId);
 
     // Our navStart will be the last frame navigation in the trace
-    const navigationStart = frameEvents.filter(e => e.name === 'navigationStart').pop();
+    const navigationStart = frameEvents.filter(TraceOfTab.isNavigationStartOfInterest).pop();
     if (!navigationStart) throw new LHError(LHError.errors.NO_NAVSTART);
 
     // Find our first paint of this frame

lighthouse-core/test/fixtures/traces/preactjs.com_ts_of_undefined.json

@@ -71,6 +71,19 @@
         "frame": "0x25edaa521e58"
       },
       "tts": 826016
+    },
+    {
+      "pid": 6117,
+      "tid": 775,
+      "ts": 1805897263653,
+      "ph": "R",
+      "cat": "blink.user_timing",
+      "name": "navigationStart",
+      "args": {
+        "frame": "0x25edaa521e58",
+        "data": {"documentLoaderURL": "intent://this-one-should-be-ignored"}
+      },
+      "tts": 673412
     },
       {
       "pid": 6117,

typings/externs.d.ts

@@ -166,6 +166,7 @@ declare global {
         fileName?: string;
         snapshot?: string;
         data?: {
+          documentLoaderURL?: string;
           frames?: {
             frame: string;
             parent?: string;