Bug 1732918 - Revert PR 29848 - Close a worker test environment in the completion callback, a=testonly

This causes sharedworker tests to be unstable (frequent intermittent
timeouts) in gecko.

testing/web-platform/tests/resources/testharness.js

@@ -312,13 +312,6 @@
                         status: harness_status.structured_clone(),
                         asserts: asserts.map(assert => assert.structured_clone()),
                     });
-
-                    // Close the worker after completion.
-                    // TODO: Worker tests don't have an implicit timeout, so in
-                    // cases where an async/promise test never resolves, the
-                    // completion callback won't be called and the worker won't
-                    // be closed.
-                    this_obj.close_worker();
                 });
     };
 
@@ -330,9 +323,6 @@
         return null;
     };
 
-    // Closes the worker, if applicable.
-    WorkerTestEnvironment.prototype.close_worker = function() {};
-
     /*
      * Dedicated web workers.
      * https://html.spec.whatwg.org/multipage/workers.html#dedicatedworkerglobalscope
@@ -356,10 +346,6 @@
         tests.wait_for_finish = true;
     };
 
-    DedicatedWorkerTestEnvironment.prototype.close_worker = function() {
-        self.close();
-    };
-
     /*
      * Shared web workers.
      * https://html.spec.whatwg.org/multipage/workers.html#sharedworkerglobalscope
@@ -370,19 +356,11 @@
     function SharedWorkerTestEnvironment() {
         WorkerTestEnvironment.call(this);
         var this_obj = this;
-
-        this.connected = false;
-        this.close_on_connect = false;
-
         // Shared workers receive message ports via the 'onconnect' event for
         // each connection.
         self.addEventListener("connect",
                 function(message_event) {
-                    this_obj.connected = true;
                     this_obj._add_message_port(message_event.source);
-                    if (this_obj.close_on_connect) {
-                        self.close();
-                    }
                 }, false);
     }
     SharedWorkerTestEnvironment.prototype = Object.create(WorkerTestEnvironment.prototype);
@@ -394,14 +372,6 @@
         tests.wait_for_finish = true;
     };
 
-    SharedWorkerTestEnvironment.prototype.close_worker = function() {
-        if (this.connected) {
-            self.close();
-        } else {
-            this.close_on_connect = true;
-        }
-    };
-
     /*
      * Service workers.
      * http://www.w3.org/TR/service-workers/