ServiceWorker: Merge FindSWRegistration into FindOrCreateRegistration for cleanup

BUG=452403
TEST=content_unittests --gtest_filter=ServiceWorkerDispatcherTest.*

Review URL: https://codereview.chromium.org/1017453006

Cr-Commit-Position: refs/heads/master@{#320902}

content/child/service_worker/service_worker_dispatcher.cc

@@ -273,27 +273,11 @@ WebServiceWorkerImpl* ServiceWorkerDispatcher::GetServiceWorker(
   return new WebServiceWorkerImpl(handle_ref.Pass(), sender_.get());
 }
 
-WebServiceWorkerRegistrationImpl*
-ServiceWorkerDispatcher::FindServiceWorkerRegistration(
-    const ServiceWorkerRegistrationObjectInfo& info,
-    bool adopt_handle) {
-  RegistrationObjectMap::iterator registration =
-      registrations_.find(info.handle_id);
-  if (registration == registrations_.end())
-    return NULL;
-  if (adopt_handle) {
-    // We are instructed to adopt a handle but we already have one, so
-    // adopt and destroy a handle ref.
-    ServiceWorkerRegistrationHandleReference::Adopt(info, sender_.get());
-  }
-  return registration->second;
-}
-
 WebServiceWorkerRegistrationImpl*
 ServiceWorkerDispatcher::CreateServiceWorkerRegistration(
     const ServiceWorkerRegistrationObjectInfo& info,
     bool adopt_handle) {
-  DCHECK(!FindServiceWorkerRegistration(info, adopt_handle));
+  DCHECK(!ContainsKey(registrations_, info.handle_id));
   if (info.handle_id == kInvalidServiceWorkerRegistrationHandleId)
     return NULL;
 
@@ -683,20 +667,21 @@ WebServiceWorkerRegistrationImpl*
 ServiceWorkerDispatcher::FindOrCreateRegistration(
     const ServiceWorkerRegistrationObjectInfo& info,
     const ServiceWorkerVersionAttributes& attrs) {
-  WebServiceWorkerRegistrationImpl* registration =
-      FindServiceWorkerRegistration(info, true);
-  if (!registration) {
-    registration = CreateServiceWorkerRegistration(info, true);
-    registration->SetInstalling(GetServiceWorker(attrs.installing, true));
-    registration->SetWaiting(GetServiceWorker(attrs.waiting, true));
-    registration->SetActive(GetServiceWorker(attrs.active, true));
-  } else {
-    // |registration| must already have version attributes, so adopt and destroy
-    // handle refs for them.
+  RegistrationObjectMap::iterator found = registrations_.find(info.handle_id);
+  if (found != registrations_.end()) {
+    ServiceWorkerRegistrationHandleReference::Adopt(info, sender_.get());
     ServiceWorkerHandleReference::Adopt(attrs.installing, sender_.get());
     ServiceWorkerHandleReference::Adopt(attrs.waiting, sender_.get());
     ServiceWorkerHandleReference::Adopt(attrs.active, sender_.get());
+    return found->second;
   }
+
+  bool adopt_handle = true;
+  WebServiceWorkerRegistrationImpl* registration =
+      CreateServiceWorkerRegistration(info, adopt_handle);
+  registration->SetInstalling(GetServiceWorker(attrs.installing, adopt_handle));
+  registration->SetWaiting(GetServiceWorker(attrs.waiting, adopt_handle));
+  registration->SetActive(GetServiceWorker(attrs.active, adopt_handle));
   return registration;
 }
 

content/child/service_worker/service_worker_dispatcher.h

@@ -112,14 +112,6 @@ class CONTENT_EXPORT ServiceWorkerDispatcher
       const ServiceWorkerObjectInfo& info,
       bool adopt_handle);
 
-  // Finds a WebServiceWorkerRegistrationImpl for the specified registration.
-  // If it's not found, returns NULL. If |adopt_handle| is true,
-  // a ServiceWorkerRegistrationHandleReference will be adopted for the
-  // registration.
-  WebServiceWorkerRegistrationImpl* FindServiceWorkerRegistration(
-      const ServiceWorkerRegistrationObjectInfo& info,
-      bool adopt_handle);
-
   // Creates a WebServiceWorkerRegistrationImpl for the specified registration
   // and transfers its ownership to the caller. If |adopt_handle| is true, a
   // ServiceWorkerRegistrationHandleReference will be adopted for the
@@ -234,6 +226,11 @@ class CONTENT_EXPORT ServiceWorkerDispatcher
   void RemoveServiceWorkerRegistration(
       int registration_handle_id);
 
+  // Returns an existing registration or new one filled in with version
+  // attributes. This function assumes given |info| and |attrs| retain handle
+  // references and always adopts them.
+  // TODO(nhiroki): This assumption seems to impair readability. We could
+  // explictly pass ServiceWorker(Registration)HandleReference instead.
   WebServiceWorkerRegistrationImpl* FindOrCreateRegistration(
       const ServiceWorkerRegistrationObjectInfo& info,
       const ServiceWorkerVersionAttributes& attrs);