Support adding iframes with srcdoc attributes in remote context helper.

This makes executor-window.py a bit smarter
- have it pass the UUID when starting the executor.
- move extra-script handling for the window executor into the python
- move extracting `startOn` param into the python

This makes it possible to just put the whole thing into the srcdoc attribute (after fixing some URL generating code to handle srcdocs).


Bug: 1491597
Change-Id: Ib4825ad7f117fd9db04a4203315989ec1c26412c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4979845
Reviewed-by: Domenic Denicola <domenic@chromium.org>
Commit-Queue: Fergal Daly <fergal@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1216784}

third_party/blink/web_tests/external/wpt/common/dispatcher/dispatcher.js

@@ -1,7 +1,26 @@
 // Define a universal message passing API. It works cross-origin and across
 // browsing context groups.
 const dispatcher_path = "/common/dispatcher/dispatcher.py";
-const dispatcher_url = new URL(dispatcher_path, location.href).href;
+
+// Finds the nearest ancestor window that has a non srcdoc location. This should
+// give us a usable location for constructing further URLs.
+function findLocationFromAncestors(w) {
+  if (w.location.href == 'about:srcdoc') {
+    return findLocationFromAncestors(w.parent);
+  }
+  return w.location;
+}
+
+// Handles differences between workers vs frames (src vs srcdoc).
+function findLocation() {
+  if (location.href == 'about:srcdoc') {
+    return findLocationFromAncestors(window.parent);
+  }
+  return location;
+}
+
+const dispatcherLocation = findLocation();
+const dispatcher_url = new URL(dispatcher_path, dispatcherLocation).href;
 
 // Return a promise, limiting the number of concurrent accesses to a shared
 // resources to |max_concurrent_access|.
@@ -138,7 +157,7 @@ const cacheableShowRequestHeaders = function(origin, uuid) {
 //   protocol: (optional) Sets the returned URL's `protocol` property.
 // }
 function remoteExecutorUrl(uuid, options) {
-  const url = new URL("/common/dispatcher/remote-executor.html", location);
+  const url = new URL("/common/dispatcher/remote-executor.html", dispatcherLocation);
   url.searchParams.set("uuid", uuid);
 
   if (options?.host) {

third_party/blink/web_tests/external/wpt/html/browsers/browsing-the-web/remote-context-helper-tests/addIframe-srcdoc-startOn.window.js

@@ -0,0 +1,24 @@
+// META: title=RemoteContextWrapper addIframe with srcdoc and startOn
+// META: script=/common/dispatcher/dispatcher.js
+// META: script=/common/get-host-info.sub.js
+// META: script=/common/utils.js
+// META: script=/html/browsers/browsing-the-web/remote-context-helper/resources/remote-context-helper.js
+// META: script=./resources/test-helper.js
+
+'use strict';
+
+promise_test(async t => {
+  const rcHelper = new RemoteContextHelper();
+
+  const main = await rcHelper.addWindow();
+
+  const iframe = await main.addIframeSrcdoc(
+      /*extraConfig=*/ {startOn: 'pageshow'});
+
+  await assertSimplestScriptRuns(iframe);
+  await assert_equals(
+      await iframe.executeScript(() => {
+        return executorStartEvent.type;
+      }),
+      'pageshow');
+});

third_party/blink/web_tests/external/wpt/html/browsers/browsing-the-web/remote-context-helper-tests/addIframe-srcdoc.window.js

@@ -0,0 +1,27 @@
+// META: title=RemoteContextWrapper addIframe with srcdoc
+// META: script=/common/dispatcher/dispatcher.js
+// META: script=/common/get-host-info.sub.js
+// META: script=/common/utils.js
+// META: script=/html/browsers/browsing-the-web/remote-context-helper/resources/remote-context-helper.js
+// META: script=./resources/test-helper.js
+
+'use strict';
+
+// This tests that arguments passed to the constructor are respected.
+promise_test(async t => {
+  const rcHelper = new RemoteContextHelper();
+
+  const main = await rcHelper.addWindow();
+
+  const iframe = await main.addIframeSrcdoc(
+      /*extraConfig=*/ {scripts: ['./resources/test-script.js']},
+      /*attributes=*/ {id: 'test-id'},
+  );
+
+  await assertSimplestScriptRuns(iframe);
+  await assertFunctionRuns(iframe, () => testFunction(), 'testFunction exists');
+
+  assert_equals(
+      await main.executeScript(() => document.getElementById('test-id').id),
+      'test-id', 'verify id');
+});

third_party/blink/web_tests/external/wpt/html/browsers/browsing-the-web/remote-context-helper/resources/executor-common.js

@@ -9,9 +9,6 @@ function addScripts(urls) {
   return Promise.all(urls.map(addScript));
 }
 
-function startExecutor() {
-  const params = new URLSearchParams(location.search);
-  addScripts(params.getAll('script'));
-  const uuid = params.get('uuid');
+function startExecutor(uuid) {
   executor = new Executor(uuid);
 }

third_party/blink/web_tests/external/wpt/html/browsers/browsing-the-web/remote-context-helper/resources/executor-window.js

@@ -4,17 +4,14 @@
 
 let executorStartEvent = null;
 
-function requestExecutor() {
-  const params = new URLSearchParams(location.search);
-  const startOn = params.get('startOn');
-
+function requestExecutor(uuid, startOn) {
   if (startOn) {
     addEventListener(startOn, (e) => {
       executorStartEvent = e;
-      startExecutor();
+      startExecutor(uuid);
     });
   } else {
-    startExecutor();
+    startExecutor(uuid);
   }
 }
 

third_party/blink/web_tests/external/wpt/html/browsers/browsing-the-web/remote-context-helper/resources/executor-window.py

@@ -1,4 +1,6 @@
+import html
 import json
+from urllib import parse
 
 def main(request, response):
   initRequestHeaders = ""
@@ -11,17 +13,28 @@ def main(request, response):
             status = int(request.GET.first(b"status"))
       else:
             status = 200
+  query = parse.parse_qs(request.url_parts.query)
+  scripts = []
+  for script in query.get("script", []):
+    scripts.append(f"<script src='{html.escape(script)}'></script>")
+  scripts_s = "\n".join(scripts)
+
+  uuid = query.get("uuid")[0]
+
+  start_on = query.get("startOn")
+  start_on_s = f"'{start_on[0]}'" if start_on else "null"
 
   return (status, [("Content-Type", "text/html")], f"""
 <!DOCTYPE HTML>
 <script src="/common/dispatcher/dispatcher.js"></script>
 <script src="./executor-common.js"></script>
 <script src="./executor-window.js"></script>
 
+{scripts_s}
 <body>
 <script>
 window.__requestHeaders = new Headers();
 {initRequestHeaders}
-requestExecutor();
+requestExecutor("{uuid}", {start_on_s});
 </script>
 """)

third_party/blink/web_tests/external/wpt/html/browsers/browsing-the-web/remote-context-helper/resources/executor-worker.js

@@ -6,4 +6,7 @@ function addScript(url) {
   importScripts(url);
 }
 
-startExecutor();
+const params = new URLSearchParams(location.search);
+addScripts(params.getAll('script'));
+
+startExecutor(params.get('uuid'));

third_party/blink/web_tests/external/wpt/html/browsers/browsing-the-web/remote-context-helper/resources/remote-context-helper.js

@@ -299,6 +299,17 @@
     };
   }
 
+  function iframeSrcdocExecutorCreator(remoteContextWrapper, attributes) {
+    return async (url) => {
+      // `url` points to the content needed to run an `Executor` in the frame.
+      // So we download the content and pass it via the `srcdoc` attribute,
+      // setting the iframe's `src` to `undefined`.
+      attributes['srcdoc'] = await fetch(url).then(r => r.text());
+      elementExecutorCreator(
+          remoteContextWrapper, 'iframe', attributes)(undefined);
+    };
+  }
+
   function workerExecutorCreator() {
     return url => {
       new Worker(url);
@@ -370,7 +381,7 @@
     }
 
     /**
-     * Adds an iframe to the current document.
+     * Adds an iframe with `src` attribute to the current document.
      * @param {RemoteContextConfig} [extraConfig]
      * @param {[string, string][]} [attributes] A list of pairs of strings
      *     of attribute name and value these will be set on the iframe element
@@ -384,6 +395,21 @@
       });
     }
 
+    /**
+     * Adds an iframe with `srcdoc` attribute to the current document
+     * @param {RemoteContextConfig} [extraConfig]
+     * @param {[string, string][]} [attributes] A list of pairs of strings
+     *     of attribute name and value these will be set on the iframe element
+     *     when added to the document.
+     * @returns {Promise<RemoteContextWrapper>} The remote context.
+     */
+    addIframeSrcdoc(extraConfig, attributes = {}) {
+      return this.helper.createContext({
+        executorCreator: iframeSrcdocExecutorCreator(this, attributes),
+        extraConfig,
+      });
+    }
+
     /**
      * Adds a dedicated worker to the current document.
      * @param {RemoteContextConfig} [extraConfig]