Bug 1595964 Part 1 - Add nsIServiceWorkerRegistrationInfo.evaluatingWorker, r=asuth.

Differential Revision: https://phabricator.services.mozilla.com/D54286

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

dom/interfaces/base/nsIServiceWorkerManager.idl

@@ -58,6 +58,9 @@ interface nsIServiceWorkerInfo : nsISupports
 
   readonly attribute nsIWorkerDebugger debugger;
 
+  // Return whether the ServiceWorker has a "fetch" event listener. Throws if
+  // this is unknown because the worker's main script hasn't finished executing
+  // (when exposed as evaluatingWorker).
   readonly attribute bool handlesFetchEvents;
 
   readonly attribute PRTime installedTime;
@@ -91,6 +94,7 @@ interface nsIServiceWorkerRegistrationInfo : nsISupports
 
   readonly attribute PRTime lastUpdateTime;
 
+  readonly attribute nsIServiceWorkerInfo evaluatingWorker;
   readonly attribute nsIServiceWorkerInfo installingWorker;
   readonly attribute nsIServiceWorkerInfo waitingWorker;
   readonly attribute nsIServiceWorkerInfo activeWorker;

dom/serviceworkers/ServiceWorkerInfo.cpp

@@ -91,6 +91,11 @@ NS_IMETHODIMP
 ServiceWorkerInfo::GetHandlesFetchEvents(bool* aValue) {
   MOZ_ASSERT(aValue);
   MOZ_ASSERT(NS_IsMainThread());
+
+  if (mHandlesFetch == Unknown) {
+    return NS_ERROR_FAILURE;
+  }
+
   *aValue = HandlesFetch();
   return NS_OK;
 }

dom/serviceworkers/ServiceWorkerRegistrationInfo.cpp

@@ -170,7 +170,7 @@ ServiceWorkerRegistrationInfo::GetScope(nsAString& aScope) {
 NS_IMETHODIMP
 ServiceWorkerRegistrationInfo::GetScriptSpec(nsAString& aScriptSpec) {
   MOZ_ASSERT(NS_IsMainThread());
-  RefPtr<ServiceWorkerInfo> newest = Newest();
+  RefPtr<ServiceWorkerInfo> newest = NewestIncludingEvaluating();
   if (newest) {
     CopyUTF8toUTF16(newest->ScriptSpec(), aScriptSpec);
   }
@@ -191,6 +191,15 @@ ServiceWorkerRegistrationInfo::GetLastUpdateTime(PRTime* _retval) {
   return NS_OK;
 }
 
+NS_IMETHODIMP
+ServiceWorkerRegistrationInfo::GetEvaluatingWorker(
+    nsIServiceWorkerInfo** aResult) {
+  MOZ_ASSERT(NS_IsMainThread());
+  RefPtr<ServiceWorkerInfo> info = mEvaluatingWorker;
+  info.forget(aResult);
+  return NS_OK;
+}
+
 NS_IMETHODIMP
 ServiceWorkerRegistrationInfo::GetInstallingWorker(
     nsIServiceWorkerInfo** aResult) {
@@ -530,6 +539,11 @@ void ServiceWorkerRegistrationInfo::SetEvaluating(
   MOZ_ASSERT(mActiveWorker != aServiceWorker);
 
   mEvaluatingWorker = aServiceWorker;
+
+  // We don't call UpdateRegistrationState() here because the evaluating worker
+  // is currently not exposed to content on the registration, so calling it here
+  // would produce redundant IPC traffic.
+  NotifyChromeRegistrationListeners();
 }
 
 void ServiceWorkerRegistrationInfo::ClearEvaluating() {
@@ -543,6 +557,9 @@ void ServiceWorkerRegistrationInfo::ClearEvaluating() {
   // We don't update the redundant time for the sw here, since we've not expose
   // evalutingWorker yet.
   mEvaluatingWorker = nullptr;
+
+  // As for SetEvaluating, UpdateRegistrationState() does not need to be called.
+  NotifyChromeRegistrationListeners();
 }
 
 void ServiceWorkerRegistrationInfo::ClearInstalling() {

dom/serviceworkers/ServiceWorkerRegistrationInfo.h

@@ -104,6 +104,14 @@ class ServiceWorkerRegistrationInfo final
     return newest.forget();
   }
 
+  already_AddRefed<ServiceWorkerInfo> NewestIncludingEvaluating() const {
+    if (mEvaluatingWorker) {
+      RefPtr<ServiceWorkerInfo> newest = mEvaluatingWorker;
+      return newest.forget();
+    }
+    return Newest();
+  }
+
   already_AddRefed<ServiceWorkerInfo> GetServiceWorkerInfoById(uint64_t aId);
 
   void StartControllingClient() {