Enable spare RenderProcessHost to be preinitialized.

content/browser/storage_partition_impl.cc

Index: content/browser/storage_partition_impl.cc
diff --git a/content/browser/storage_partition_impl.cc b/content/browser/storage_partition_impl.cc
index 5c4270512f9614eafefc00b3d70723b7c9f8f3cd..aa7f8e742ec65ba92b5acfba425b47c9862c56be 100644
--- a/content/browser/storage_partition_impl.cc
+++ b/content/browser/storage_partition_impl.cc
@@ -22,6 +22,7 @@
 #include "content/browser/fileapi/browser_file_system_helper.h"
 #include "content/browser/gpu/shader_cache_factory.h"
 #include "content/browser/notifications/platform_notification_context_impl.h"
+#include "content/browser/renderer_host/render_process_host_impl.h"
 #include "content/common/dom_storage/dom_storage_types.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/browser_thread.h"
@@ -401,6 +402,8 @@ StoragePartitionImpl::~StoragePartitionImpl() {
         base::Bind(&storage::DatabaseTracker::Shutdown, GetDatabaseTracker()));
   }
 
+  RenderProcessHostImpl::OnStoragePartitionShutdown(this);
+
   if (GetFileSystemContext())
     GetFileSystemContext()->Shutdown();