diff --git a/dom/cache/CacheStorage.cpp b/dom/cache/CacheStorage.cpp
index 8e600556fd5c..bc2ede67dded 100644
--- a/dom/cache/CacheStorage.cpp
+++ b/dom/cache/CacheStorage.cpp
@@ -50,11 +50,10 @@ NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(mozilla::dom::cache::CacheStorage,
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(CacheStorage)
   NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
   NS_INTERFACE_MAP_ENTRY(nsISupports)
-  NS_INTERFACE_MAP_ENTRY(nsIIPCBackgroundChildCreateCallback)
 NS_INTERFACE_MAP_END
 
 // We cannot reference IPC types in a webidl binding implementation header.  So
-// define this in the .cpp and use heap storage in the mPendingRequests list.
+// define this in the .cpp.
 struct CacheStorage::Entry final
 {
   RefPtr<Promise> mPromise;
@@ -275,7 +274,6 @@ CacheStorage::CacheStorage(Namespace aNamespace, nsIGlobalObject* aGlobal,
   : mNamespace(aNamespace)
   , mGlobal(aGlobal)
   , mPrincipalInfo(MakeUnique<PrincipalInfo>(aPrincipalInfo))
-  , mWorkerHolder(aWorkerHolder)
   , mActor(nullptr)
   , mStatus(NS_OK)
 {
@@ -283,19 +281,26 @@ CacheStorage::CacheStorage(Namespace aNamespace, nsIGlobalObject* aGlobal,
 
   // If the PBackground actor is already initialized then we can
   // immediately use it
-  PBackgroundChild* actor = BackgroundChild::GetForCurrentThread();
-  if (actor) {
-    ActorCreated(actor);
+  PBackgroundChild* actor = BackgroundChild::GetOrCreateForCurrentThread();
+  if (NS_WARN_IF(!actor)) {
+    mStatus = NS_ERROR_UNEXPECTED;
     return;
   }
 
-  // Otherwise we must begin the PBackground initialization process and
-  // wait for the async ActorCreated() callback.
-  MOZ_ASSERT(NS_IsMainThread());
-  bool ok = BackgroundChild::GetOrCreateForCurrentThread(this);
-  if (NS_WARN_IF(!ok)) {
-    ActorFailed();
+  // WorkerHolder ownership is passed to the CacheStorageChild actor and any
+  // actors it may create.  The WorkerHolder will keep the worker thread alive
+  // until the actors can gracefully shutdown.
+  CacheStorageChild* newActor = new CacheStorageChild(this, aWorkerHolder);
+  PCacheStorageChild* constructedActor =
+    actor->SendPCacheStorageConstructor(newActor, mNamespace, *mPrincipalInfo);
+
+  if (NS_WARN_IF(!constructedActor)) {
+    mStatus = NS_ERROR_UNEXPECTED;
+    return;
   }
+
+  MOZ_DIAGNOSTIC_ASSERT(constructedActor == newActor);
+  mActor = newActor;
 }
 
 CacheStorage::CacheStorage(nsresult aFailureResult)
@@ -336,8 +341,7 @@ CacheStorage::Match(JSContext* aCx, const RequestOrUSVString& aRequest,
   entry->mArgs = StorageMatchArgs(CacheRequest(), params, GetOpenMode());
   entry->mRequest = request;
 
-  mPendingRequests.AppendElement(entry.forget());
-  MaybeRunPendingRequests();
+  RunRequest(Move(entry));
 
   return promise.forget();
 }
@@ -361,8 +365,7 @@ CacheStorage::Has(const nsAString& aKey, ErrorResult& aRv)
   entry->mPromise = promise;
   entry->mArgs = StorageHasArgs(nsString(aKey));
 
-  mPendingRequests.AppendElement(entry.forget());
-  MaybeRunPendingRequests();
+  RunRequest(Move(entry));
 
   return promise.forget();
 }
@@ -386,8 +389,7 @@ CacheStorage::Open(const nsAString& aKey, ErrorResult& aRv)
   entry->mPromise = promise;
   entry->mArgs = StorageOpenArgs(nsString(aKey));
 
-  mPendingRequests.AppendElement(entry.forget());
-  MaybeRunPendingRequests();
+  RunRequest(Move(entry));
 
   return promise.forget();
 }
@@ -411,8 +413,7 @@ CacheStorage::Delete(const nsAString& aKey, ErrorResult& aRv)
   entry->mPromise = promise;
   entry->mArgs = StorageDeleteArgs(nsString(aKey));
 
-  mPendingRequests.AppendElement(entry.forget());
-  MaybeRunPendingRequests();
+  RunRequest(Move(entry));
 
   return promise.forget();
 }
@@ -436,8 +437,7 @@ CacheStorage::Keys(ErrorResult& aRv)
   entry->mPromise = promise;
   entry->mArgs = StorageKeysArgs();
 
-  mPendingRequests.AppendElement(entry.forget());
-  MaybeRunPendingRequests();
+  RunRequest(Move(entry));
 
   return promise.forget();
 }
@@ -498,66 +498,19 @@ CacheStorage::WrapObject(JSContext* aContext, JS::Handle<JSObject*> aGivenProto)
   return mozilla::dom::CacheStorageBinding::Wrap(aContext, this, aGivenProto);
 }
 
-void
-CacheStorage::ActorCreated(PBackgroundChild* aActor)
-{
-  NS_ASSERT_OWNINGTHREAD(CacheStorage);
-  MOZ_DIAGNOSTIC_ASSERT(aActor);
-
-  if (NS_WARN_IF(mWorkerHolder && mWorkerHolder->Notified())) {
-    ActorFailed();
-    return;
-  }
-
-  // WorkerHolder ownership is passed to the CacheStorageChild actor and any
-  // actors it may create.  The WorkerHolder will keep the worker thread alive
-  // until the actors can gracefully shutdown.
-  CacheStorageChild* newActor = new CacheStorageChild(this, mWorkerHolder);
-  PCacheStorageChild* constructedActor =
-    aActor->SendPCacheStorageConstructor(newActor, mNamespace, *mPrincipalInfo);
-
-  if (NS_WARN_IF(!constructedActor)) {
-    ActorFailed();
-    return;
-  }
-
-  mWorkerHolder = nullptr;
-
-  MOZ_DIAGNOSTIC_ASSERT(constructedActor == newActor);
-  mActor = newActor;
-
-  MaybeRunPendingRequests();
-  MOZ_DIAGNOSTIC_ASSERT(mPendingRequests.IsEmpty());
-}
-
-void
-CacheStorage::ActorFailed()
-{
-  NS_ASSERT_OWNINGTHREAD(CacheStorage);
-  MOZ_DIAGNOSTIC_ASSERT(!NS_FAILED(mStatus));
-
-  mStatus = NS_ERROR_UNEXPECTED;
-  mWorkerHolder = nullptr;
-
-  for (uint32_t i = 0; i < mPendingRequests.Length(); ++i) {
-    nsAutoPtr<Entry> entry(mPendingRequests[i].forget());
-    entry->mPromise->MaybeReject(NS_ERROR_UNEXPECTED);
-  }
-  mPendingRequests.Clear();
-}
-
 void
 CacheStorage::DestroyInternal(CacheStorageChild* aActor)
 {
   NS_ASSERT_OWNINGTHREAD(CacheStorage);
   MOZ_DIAGNOSTIC_ASSERT(mActor);
   MOZ_DIAGNOSTIC_ASSERT(mActor == aActor);
+  MOZ_DIAGNOSTIC_ASSERT(!NS_FAILED(mStatus));
   mActor->ClearListener();
   mActor = nullptr;
+  mStatus = NS_ERROR_UNEXPECTED;
 
   // Note that we will never get an actor again in case another request is
   // made before this object is destructed.
-  ActorFailed();
 }
 
 nsIGlobalObject*
@@ -595,26 +548,24 @@ CacheStorage::~CacheStorage()
 }
 
 void
-CacheStorage::MaybeRunPendingRequests()
+CacheStorage::RunRequest(nsAutoPtr<Entry>&& aEntry)
 {
-  if (!mActor) {
-    return;
-  }
+  MOZ_ASSERT(mActor);
 
-  for (uint32_t i = 0; i < mPendingRequests.Length(); ++i) {
+  nsAutoPtr<Entry> entry(Move(aEntry));
+
+  AutoChildOpArgs args(this, entry->mArgs, 1);
+
+  if (entry->mRequest) {
     ErrorResult rv;
-    nsAutoPtr<Entry> entry(mPendingRequests[i].forget());
-    AutoChildOpArgs args(this, entry->mArgs, 1);
-    if (entry->mRequest) {
-      args.Add(entry->mRequest, IgnoreBody, IgnoreInvalidScheme, rv);
-    }
+    args.Add(entry->mRequest, IgnoreBody, IgnoreInvalidScheme, rv);
     if (NS_WARN_IF(rv.Failed())) {
       entry->mPromise->MaybeReject(rv);
-      continue;
+      return;
     }
-    mActor->ExecuteOp(mGlobal, entry->mPromise, this, args.SendAsOpArgs());
   }
-  mPendingRequests.Clear();
+
+  mActor->ExecuteOp(mGlobal, entry->mPromise, this, args.SendAsOpArgs());
 }
 
 OpenMode
diff --git a/dom/cache/CacheStorage.h b/dom/cache/CacheStorage.h
index b3f7e62c738f..2ba60dcd769a 100644
--- a/dom/cache/CacheStorage.h
+++ b/dom/cache/CacheStorage.h
@@ -14,7 +14,6 @@
 #include "nsISupportsImpl.h"
 #include "nsTArray.h"
 #include "nsWrapperCache.h"
-#include "nsIIPCBackgroundChildCreateCallback.h"
 
 class nsIGlobalObject;
 
@@ -40,7 +39,7 @@ namespace cache {
 class CacheStorageChild;
 class CacheWorkerHolder;
 
-class CacheStorage final : public nsIIPCBackgroundChildCreateCallback
+class CacheStorage final : public nsISupports
                          , public nsWrapperCache
                          , public TypeUtils
 {
@@ -79,10 +78,6 @@ public:
   nsISupports* GetParentObject() const;
   virtual JSObject* WrapObject(JSContext* aContext, JS::Handle<JSObject*> aGivenProto) override;
 
-  // nsIIPCbackgroundChildCreateCallback methods
-  virtual void ActorCreated(PBackgroundChild* aActor) override;
-  virtual void ActorFailed() override;
-
   // Called when CacheStorageChild actor is being destroyed
   void DestroyInternal(CacheStorageChild* aActor);
 
@@ -102,7 +97,8 @@ private:
   explicit CacheStorage(nsresult aFailureResult);
   ~CacheStorage();
 
-  void MaybeRunPendingRequests();
+  struct Entry;
+  void RunRequest(nsAutoPtr<Entry>&& aEntry);
 
   OpenMode
   GetOpenMode() const;
@@ -110,20 +106,15 @@ private:
   const Namespace mNamespace;
   nsCOMPtr<nsIGlobalObject> mGlobal;
   UniquePtr<mozilla::ipc::PrincipalInfo> mPrincipalInfo;
-  RefPtr<CacheWorkerHolder> mWorkerHolder;
 
   // weak ref cleared in DestroyInternal
   CacheStorageChild* mActor;
 
-  struct Entry;
-  nsTArray<nsAutoPtr<Entry>> mPendingRequests;
-
   nsresult mStatus;
 
 public:
   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
-  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS_AMBIGUOUS(CacheStorage,
-                                           nsIIPCBackgroundChildCreateCallback)
+  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(CacheStorage)
 };
 
 } // namespace cache