Revert "Create ServiceWorkerProviderHost before starting worker"

content/browser/service_worker/service_worker_version.h

Index: content/browser/service_worker/service_worker_version.h
diff --git a/content/browser/service_worker/service_worker_version.h b/content/browser/service_worker/service_worker_version.h
index 5ed49bfb5cfcc983cb8a974deeaff1a2a35de03f..e53d2169c8e27248cf7d81b33128592767350a24 100644
--- a/content/browser/service_worker/service_worker_version.h
+++ b/content/browser/service_worker/service_worker_version.h
@@ -298,13 +298,6 @@ class CONTENT_EXPORT ServiceWorkerVersion
     return controllee_map_;
   }
 
-  // The provider host hosting this version. Only valid while the version is
-  // running.
-  ServiceWorkerProviderHost* provider_host() {
-    DCHECK(provider_host_);
-    return provider_host_.get();
-  }
-
   base::WeakPtr<ServiceWorkerContextCore> context() const { return context_; }
 
   // Adds and removes |request_job| as a dependent job not to stop the
@@ -718,11 +711,6 @@ class CONTENT_EXPORT ServiceWorkerVersion
 
   std::set<const ServiceWorkerURLRequestJob*> streaming_url_request_jobs_;
 
-  // Keeps track of the provider hosting this running service worker for this
-  // version. |provider_host_| is always valid as long as this version is
-  // running.
-  base::WeakPtr<ServiceWorkerProviderHost> provider_host_;
-
   std::map<std::string, ServiceWorkerProviderHost*> controllee_map_;
   // Will be null while shutting down.
   base::WeakPtr<ServiceWorkerContextCore> context_;