Disallow certain blocking DOM calls during microtask execution.

third_party/WebKit/LayoutTests/http/tests/security/suborigins/crossorigin/suborigin-cors-fetch-failure-output.php

Index: third_party/WebKit/LayoutTests/http/tests/security/suborigins/crossorigin/suborigin-cors-fetch-failure-output.php
diff --git a/third_party/WebKit/LayoutTests/http/tests/security/suborigins/crossorigin/suborigin-cors-fetch-failure-output.php b/third_party/WebKit/LayoutTests/http/tests/security/suborigins/crossorigin/suborigin-cors-fetch-failure-output.php
index 0233ec42b9e603b0878607b611746364664fdcaf..582f43b0e9dfe90fdb2c70425a8c7babcd04d3d0 100644
--- a/third_party/WebKit/LayoutTests/http/tests/security/suborigins/crossorigin/suborigin-cors-fetch-failure-output.php
+++ b/third_party/WebKit/LayoutTests/http/tests/security/suborigins/crossorigin/suborigin-cors-fetch-failure-output.php
@@ -12,12 +12,12 @@ if (window.testRunner) {
 console.log("If a Suborigin makes a request, a response without an Access-Control-Allow-Suborigin header should fail and should output a reasonable error message.");
 
 function success() {
-    alert("PASS: Fetch correctly failed");
+    console.log("PASS: Fetch correctly failed");
     next();
 }
 
 function failure() {
-    alert("FAIL: Fetch incorrectly succeeded");
+    console.log("FAIL: Fetch incorrectly succeeded");
     next();
 }