Added validation of the policy specified in the 'csp' attribute

third_party/WebKit/LayoutTests/external/wpt/content-security-policy/embedded-enforcement/support/testharness-helper.sub.js

 const Host = {
   SAME_ORIGIN: "same-origin",
   CROSS_ORIGIN: "cross-origin",
 };
 
 const PolicyHeader = {
   CSP: "echo-policy.py?policy=",
   CSP_MULTIPLE: "echo-policy-multiple.py",
   REQUIRED_CSP: "echo-required-csp.py",
   ALLOW_CSP_FROM: "echo-allow-csp-from.py",
@@ skipping 58 matching lines @@
 }
 
 function assert_required_csp(t, url, csp, expected) {
   var i = document.createElement('iframe');
   if(csp)
     i.csp = csp;
   i.src = url;
 
   window.addEventListener('message', t.step_func(e => {
     if (e.source != i.contentWindow || !('required_csp' in e.data))
-        return;
-    assert_equals(expected, e.data['required_csp']);
+      return;
+    assert_equals(e.data['required_csp'], expected);
     t.done();
   }));
 
   document.body.appendChild(i);
 }
 
 function assert_iframe_with_csp(t, url, csp, shouldBlock, urlId, blockedURI) {
   var i = document.createElement('iframe');
   url.searchParams.append("id", urlId);
   i.src = url.toString();
@@ skipping 36 matching lines @@
     // Assert iframe loads.
     i.onload = t.step_func(function () {
       // Delay the check until after the postMessage has a chance to execute.
       setTimeout(t.step_func_done(function () {
         assert_true(loaded[urlId]);
       }), 1);
     });
   }
   document.body.appendChild(i);
 }