[credentialless] WPT cookie full credentialless.

New WPT tests.

From a main document using COEP:credentialless, opens iframes and load
subresources from them. Cross-origin iframes must be loaded with no
credentials for all type of resources. This tests check make the origin
of the resource and the iframe to vary, and verify what happens.

The next patch will had similar tests, but with the localStorage.

Bug: 1175099
Change-Id: I7766e80af04e3302c9c9ce9e2a3586eb02370167
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2723531
Reviewed-by: Mike West <mkwst@chromium.org>
Commit-Queue: Arthur Sonzogni <arthursonzogni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#858512}

third_party/blink/web_tests/external/wpt/html/cross-origin-embedder-policy/credentialless/iframe-load-cookie.tentative.https-expected.txt

@@ -0,0 +1,8 @@
+This is a testharness.js-based test.
+PASS Setup
+PASS same_origin iframe can send same_origin credentials
+FAIL same_origin iframe can't send cross_origin credentials assert_equals: expected (undefined) undefined but got (string) "cross_origin"
+FAIL cross_origin iframe can send cross_origin credentials assert_equals: expected (undefined) undefined but got (string) "cross_origin"
+FAIL Cross origin iframe can't send same_origin credentials assert_equals: expected (undefined) undefined but got (string) "same_origin"
+Harness: the test ran to completion.
+

third_party/blink/web_tests/external/wpt/html/cross-origin-embedder-policy/credentialless/iframe-load-cookie.tentative.https.html

@@ -0,0 +1,108 @@
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<script src="/common/utils.js"></script>
+<script src="./resources/common.js"></script>
+<script src="./resources/dispatcher.js"></script>
+<script>
+
+const same_origin = get_host_info().HTTPS_ORIGIN;
+const cross_origin = get_host_info().HTTPS_REMOTE_ORIGIN;
+const cookie_key = "coep_credentialless_iframe_load_cookie";
+const cookie_same_origin = "same_origin";
+const cookie_cross_origin = "cross_origin";
+
+// Open a new window with a given |origin|, loaded with COEP:credentialless. The
+// new document will execute any scripts sent toward the token it returns.
+const newCredentiallessWindow = (origin) => {
+  const main_document_token = token();
+  const url = origin + executor_path + coep_credentialless +
+    `&uuid=${main_document_token}`;
+  const w = window.open(url);
+  add_completion_callback(() => w.close());
+  return main_document_token;
+};
+
+// Create a new iframe, loaded with COEP:credentialless.
+// The new document will execute any scripts sent toward the token it returns.
+const newCredentiallessIframe = (parent_token, child_origin) => {
+  const sub_document_token = token();
+  const iframe_url = child_origin + executor_path + coep_credentialless +
+    `&uuid=${sub_document_token}`;
+  send(parent_token, `
+    let iframe = document.createElement("iframe");
+    iframe.src = "${iframe_url}";
+    document.body.appendChild(iframe);
+  `)
+  return sub_document_token;
+};
+
+// Fetch a resource, returns the HTTP request cookies.
+const cookieFromResource = async (document_token, resource_origin) => {
+  const resource_token = token();
+  send(document_token, `
+    let img = document.createElement("img");
+    img.src = "${showRequestHeaders(resource_origin, resource_token)}";
+    document.body.appendChild(img);
+  `);
+  let headers = JSON.parse(await receive(resource_token));
+  return parseCookies(headers)[cookie_key];
+};
+
+promise_test_parallel(async test => {
+  // Set cookie on same_origin.
+  document.cookie = `${cookie_key}=${cookie_same_origin}`;
+
+  // Set cookie on cross_origin.
+  {
+    const w_token = token();
+    const w_url = cross_origin + executor_path + `&uuid=${w_token}`;
+    const w = window.open(w_url);
+
+    const reply_token = token();
+    send(w_token, `
+      document.cookie = "${cookie_key}=${cookie_cross_origin}";
+      send("${reply_token}", "done");
+    `);
+    assert_equals(await receive(reply_token), "done");
+    w.close();
+  }
+
+  let credentialless_window = newCredentiallessWindow(same_origin);
+
+  let iframe_same_origin =
+    newCredentiallessIframe(credentialless_window, same_origin);
+  let iframe_cross_origin =
+    newCredentiallessIframe(credentialless_window, cross_origin);
+
+  promise_test_parallel(async test => {
+    assert_equals(
+      await cookieFromResource(iframe_same_origin, same_origin),
+      cookie_same_origin
+    );
+  }, "same_origin iframe can send same_origin credentials");
+
+  promise_test_parallel(async test => {
+    assert_equals(
+      await cookieFromResource(iframe_same_origin, cross_origin),
+      undefined
+    );
+  }, "same_origin iframe can't send cross_origin credentials");
+
+  promise_test_parallel(async test => {
+    assert_equals(
+      await cookieFromResource(iframe_cross_origin, cross_origin),
+      undefined
+    );
+  }, "cross_origin iframe can send cross_origin credentials");
+
+  promise_test_parallel(async test => {
+    assert_equals(
+      await cookieFromResource(iframe_cross_origin, same_origin),
+      undefined
+    );
+  }, "Cross origin iframe can't send same_origin credentials");
+
+}, "Setup")
+
+</script>