[ServiceWorker] Allow waitUntil to be called multiple times asynchronously

third_party/WebKit/Source/modules/serviceworkers/WaitUntilObserver.h

Index: third_party/WebKit/Source/modules/serviceworkers/WaitUntilObserver.h
diff --git a/third_party/WebKit/Source/modules/serviceworkers/WaitUntilObserver.h b/third_party/WebKit/Source/modules/serviceworkers/WaitUntilObserver.h
index 85fd3a1fc13e205ef84835777b8ff367834c404f..960ae8633122410d43cdd741aaf36497d11fe8d9 100644
--- a/third_party/WebKit/Source/modules/serviceworkers/WaitUntilObserver.h
+++ b/third_party/WebKit/Source/modules/serviceworkers/WaitUntilObserver.h
@@ -54,10 +54,10 @@ class MODULES_EXPORT WaitUntilObserver final
   // These methods can be called when the lifecycle of ExtendableEvent
   // observed by this WaitUntilObserver should be extended by other reason
   // than ExtendableEvent.waitUntil.
-  // Note: There is no need to call decrementPendingActivity() after the context
+  // Note: There is no need to call DecrementPendingPromise() after the context
   // is being destroyed.
-  void IncrementPendingActivity();
-  void DecrementPendingActivity();
+  void IncrementPendingPromise();
+  void DecrementPendingPromise();
 
   DECLARE_VIRTUAL_TRACE();
 
@@ -66,12 +66,14 @@ class MODULES_EXPORT WaitUntilObserver final
   class ThenFunction;
 
   enum class EventDispatchState {
-    // Event dispatch has not yet finished.
+    // Event dispatch has not yet started.
     kInitial,
+    // Event dispatch has started but not yet finished.
+    kDispatching,
     // Event dispatch completed. There may still be outstanding waitUntil
     // promises that must settle before notifying ServiceWorkerGlobalScopeClient
     // that the event finished.
-    kCompleted,
+    kDispatched,
     // Event dispatch failed. Any outstanding waitUntil promises are ignored.
     kFailed
   };
@@ -87,10 +89,12 @@ class MODULES_EXPORT WaitUntilObserver final
 
   void ConsumeWindowInteraction(TimerBase*);
 
+  void MaybeCompleteEvent();
+
   Member<ExecutionContext> execution_context_;
   EventType type_;
   int event_id_;
-  int pending_activity_ = 0;
+  int pending_promises_ = 0;
   EventDispatchState event_dispatch_state_ = EventDispatchState::kInitial;
   bool has_rejected_promise_ = false;
   double event_dispatch_time_ = 0;