CSP3: Implement 'worker-src'.

third_party/WebKit/LayoutTests/http/tests/security/contentSecurityPolicy/resources/ping.js

+// Service Worker:
+if (typeof ServiceWorkerGlobalScope) {
+  self.onmessage = function (e) { e.source.postMessage("ping"); };
+}
+
+// Shared Workers:
+if (typeof SharedWorkerGlobalScope) {
+  onconnect = function (e) {
+    var port = e.ports[0];
+
+    port.onmessage = function () { port.postMessage("ping"); }
+    port.postMessage("ping");
+  };
+}
+
+// Dedicated web workers:

[foolip, 2016/11/09 16:17:52]

No typeof DedicatedWorkerGlobalScope? Does this rely on none of the others have
a global postMessage? Possibly fragile?

+if (self.postMessage) {
+  self.postMessage("ping");
+}