Pass approprite task runners to AssociatedBinding::Bind via ServiceWorker

This is part of efforts to replace base::ThreadTaskRunnerHandle::Get()
and SequencedTaskRunnerHandle::Get() with other appropriate task runners
in the renderer.

Bug: 786332
Change-Id: I7df2d7a4d0154d8b563c4d0e350a78c97067093b
Reviewed-on: https://chromium-review.googlesource.com/c/1293107Reviewed-by: Alexander Timin <altimin@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Hajime Hoshi <hajimehoshi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#601850}

third_party/blink/renderer/modules/service_worker/service_worker.cc

@@ -183,11 +183,15 @@ ServiceWorker::ServiceWorker(ExecutionContext* execution_context,
       state_(info.state),
       binding_(this) {
   DCHECK_NE(mojom::blink::kInvalidServiceWorkerVersionId, info.version_id);
-  host_.Bind(mojom::blink::ServiceWorkerObjectHostAssociatedPtrInfo(
-      std::move(info.host_ptr_info),
-      mojom::blink::ServiceWorkerObjectHost::Version_));
-  binding_.Bind(mojom::blink::ServiceWorkerObjectAssociatedRequest(
-      std::move(info.request)));
+  host_.Bind(
+      mojom::blink::ServiceWorkerObjectHostAssociatedPtrInfo(
+          std::move(info.host_ptr_info),
+          mojom::blink::ServiceWorkerObjectHost::Version_),
+      execution_context->GetTaskRunner(blink::TaskType::kInternalDefault));
+  binding_.Bind(
+      mojom::blink::ServiceWorkerObjectAssociatedRequest(
+          std::move(info.request)),
+      execution_context->GetTaskRunner(blink::TaskType::kInternalDefault));
 }
 
 ServiceWorker::~ServiceWorker() = default;

third_party/blink/renderer/modules/service_worker/service_worker_registration.cc

@@ -151,12 +151,16 @@ void ServiceWorkerRegistration::Attach(
     host_.Bind(
         mojom::blink::ServiceWorkerRegistrationObjectHostAssociatedPtrInfo(
             std::move(info.host_ptr_info),
-            mojom::blink::ServiceWorkerRegistrationObjectHost::Version_));
+            mojom::blink::ServiceWorkerRegistrationObjectHost::Version_),
+        GetExecutionContext()->GetTaskRunner(
+            blink::TaskType::kInternalDefault));
   }
   // The host expects us to use |info.request| so bind to it.
   binding_.Close();
-  binding_.Bind(mojom::blink::ServiceWorkerRegistrationObjectAssociatedRequest(
-      std::move(info.request)));
+  binding_.Bind(
+      mojom::blink::ServiceWorkerRegistrationObjectAssociatedRequest(
+          std::move(info.request)),
+      GetExecutionContext()->GetTaskRunner(blink::TaskType::kInternalDefault));
 
   update_via_cache_ = info.update_via_cache;
   installing_ =