Introduce WorkerStoragePartitionId and use it in SharedWorkerInstance.

content/browser/shared_worker/shared_worker_message_filter.cc

Index: content/browser/shared_worker/shared_worker_message_filter.cc
diff --git a/content/browser/shared_worker/shared_worker_message_filter.cc b/content/browser/shared_worker/shared_worker_message_filter.cc
index 551027ee27fdd57854a21947269b265646986a06..f355441b834fadaef54f5ea09560873de7cda9c1 100644
--- a/content/browser/shared_worker/shared_worker_message_filter.cc
+++ b/content/browser/shared_worker/shared_worker_message_filter.cc
@@ -24,11 +24,11 @@ SharedWorkerMessageFilter::SharedWorkerMessageFilter(
     ResourceContext* resource_context,
     const WorkerStoragePartition& partition,
     MessagePortMessageFilter* message_port_message_filter)
-    : BrowserMessageFilter(
-          kFilteredMessageClasses, arraysize(kFilteredMessageClasses)),
+    : BrowserMessageFilter(kFilteredMessageClasses,
+                           arraysize(kFilteredMessageClasses)),
       render_process_id_(render_process_id),
       resource_context_(resource_context),
-      partition_(partition),
+      partition_id_(partition),
       message_port_message_filter_(message_port_message_filter) {
 }
 
@@ -79,7 +79,7 @@ void SharedWorkerMessageFilter::OnCreateWorker(
   bool url_error = false;
   *route_id = GetNextRoutingID();
   SharedWorkerServiceImpl::GetInstance()->CreateWorker(
-      params, *route_id, this, resource_context_, partition_, &url_error);
+      params, *route_id, this, resource_context_, partition_id_, &url_error);
   if (url_error)
     *route_id = MSG_ROUTING_NONE;
 }