Bug 1544244 - fix cookie-checking in test_toolkit_securityreporter.js r=mgoodwin

Before this patch, test_toolkit_securityreporter.js would unconditionally try to
get the value of the "Cookie" header. If a header isn't available, httpd.js
apparently throws an exception. Interestingly, exceptions thrown in httpd.js
path handlers aren't reported to the test framework, so we weren't aware of
this. Additionally, the test didn't have any way of waiting until the security
report it was expecting had arrived, so it just continued on and "succeeded".
This patch addresses these issues by using "throws" to make sure no cookies are
available and by inserting extra add_test/run_next_test pairs when the test is
waiting for a report.

Differential Revision: https://phabricator.services.mozilla.com/D27613

--HG--
extra : moz-landing-system : lando

security/manager/ssl/tests/unit/test_toolkit_securityreporter.js

@@ -44,10 +44,11 @@ function getReportCheck(expectReport, expectedError) {
                               function(request, response) {
       if (expectReport) {
         let report = JSON.parse(readDataFromRequest(request));
-        Assert.equal(request.getHeader("Cookie"), "", "No cookie sent.");
+        throws(() => request.getHeader("Cookie"), /NS_ERROR_NOT_AVAILABLE/);
         Assert.equal(report.errorCode, expectedError);
         response.setStatusLine(null, 201, "Created");
         response.write("Created");
+        run_next_test(); // resolve a "test" waiting on this report to be sent/received
       } else {
         do_throw("No report should have been received");
       }
@@ -133,11 +134,13 @@ function run_test() {
   add_connection_test("good.include-subdomains.pinning.example.com",
                       PRErrorCodeSuccess, null,
                       getReportCheck(true, PRErrorCodeSuccess));
+  add_test(() => {}); // add a "test" so we wait for the report to be sent
 
   // Test sending a report where there is an error and a failed cert chain.
   add_connection_test("expired.example.com",
                       SEC_ERROR_EXPIRED_CERTIFICATE, null,
                       getReportCheck(true, SEC_ERROR_EXPIRED_CERTIFICATE));
+  add_test(() => {}); // add a "test" so we wait for the report to be sent
 
   run_next_test();
 }