Disallow connecting an insecure WebSocket from a secure page.

LayoutTests/http/tests/security/mixedContent/websocket/resources/expect-throw-on-construction.js

+function reportResult(msg) {
+    if ("opener" in self)
+        self.opener.postMessage(msg, "*");
+    else
+        postMessage(msg);
+}
+
+(function () {
+    try {
+        var ws = new WebSocket("ws://127.0.0.1:8880/echo");
+    } catch (e) {
+        reportResult("DONE");
+        return;
+    }
+    reportResult("FAIL: No exception was thrown")
+})();