ServiceWorker: add ServiceWorkerClients.claim() support (2/3).

content/browser/service_worker/service_worker_registration.h

Index: content/browser/service_worker/service_worker_registration.h
diff --git a/content/browser/service_worker/service_worker_registration.h b/content/browser/service_worker/service_worker_registration.h
index 6a8d11fcac988e4ed81c51d19563e83879575f50..4305846887617863a2b06c5e67edceff05afaa7c 100644
--- a/content/browser/service_worker/service_worker_registration.h
+++ b/content/browser/service_worker/service_worker_registration.h
@@ -109,6 +109,10 @@ class CONTENT_EXPORT ServiceWorkerRegistration
   // initiated immediately.
   void ActivateWaitingVersionWhenReady();
 
+  // Takes over control of provider hosts which are currently not controlled or
+  // controlled by other registrations.
+  void ClaimClients();
+
   // Triggers the [[ClearRegistration]] algorithm when the currently
   // active version has no controllees. Deletes this registration
   // from storage immediately.
@@ -163,6 +167,10 @@ class CONTENT_EXPORT ServiceWorkerRegistration
                          scoped_refptr<ServiceWorkerVersion> version,
                          ServiceWorkerStatusCode status);
 
+  bool ShouldClaim(
+      ServiceWorkerProviderHost* provider_host,
+      std::vector<ServiceWorkerRegistrationInfo>& registration_infos);
+
   const GURL pattern_;
   const int64 registration_id_;
   bool is_deleted_;