Allow cross-origin cssRules access to CORS-fetched stylesheet.

LayoutTests/http/tests/security/resources/link-crossorigin-common.js

 // Tiny test rig for all security/link-crossorigin-*.html tests,
 // which exercise <link> + CORS variations.
 
-self.jsTestIsAsync = true;
+window.jsTestIsAsync = true;
 
 if (window.testRunner) {
     testRunner.dumpAsText();
     testRunner.waitUntilDone();
 }
 
 // The common case is to have four sub-tests. To override
-// for a test, assign window.test_count.
-var default_test_count = 4;
+// for a test, assign window.testCount.
+var defaultTestCount = 4;
 
-var event_count = 0;
-test_count = window.test_count || default_test_count;
+var eventCount = 0;
+testCount = window.testCount || defaultTestCount;
 
-function finish(pass, msg) {
+function finish(pass, msg, event) {
     if (pass)
         testPassed(msg || "");
-     else
+    else
         testFailed(msg || "");
-    if (++event_count >= test_count)
+
+    // Verify that the stylesheet is (in)accessible.
+    // (only report failures so as to avoid subtest ordering instability.)
+    if (event !== undefined && event.target && event.target.rel === "stylesheet") {
+        for (var i = 0; i < document.styleSheets.length; ++i) {
+            if (document.styleSheets[i].href !== event.target.href)
+                continue;
+            if (event.type === "load") {
+                try {
+                    if (document.styleSheets[i].cssRules[0].cssText.length >= 0)
+                       ;
+                    if (document.styleSheets[i].cssRules[0].cssText.indexOf("green") == -1)
+                        testFailed("Failed to find occurrence of 'green' in stylesheet: " + event.target.href);
+                } catch (e) {
+                    testFailed("Failed to access contents of stylesheet: " + event.target.href);
+                }
+            } else {
+                try {
+                    // Will throw as .cssRules should return 0.
+                    if (document.styleSheets[i].cssRules[0].cssRules[0])
+                        ;
+                    testFailed("Should not be able to access contents of stylesheet: " + event.target.href);
+                } catch (e) {
+                    ;
+                }
+            }
+            break;
+        }
+    }
+    if (++eventCount >= testCount)
         finishJSTest();
 }
 
-function pass() { finish(true); }
-function fail() { finish(false); }
+function pass(event) { finish(true, "", event); }
+function fail(event) { finish(false, "", event); }