Persist sessionStorage on disk.

chrome/browser/profiles/profile_impl.cc

Index: chrome/browser/profiles/profile_impl.cc
diff --git a/chrome/browser/profiles/profile_impl.cc b/chrome/browser/profiles/profile_impl.cc
index 0e03dbe5355b85a731a3e41ba2516da121ff3f61..34b30d98b984260434fa7ceea8fdad6a210dfde3 100644
--- a/chrome/browser/profiles/profile_impl.cc
+++ b/chrome/browser/profiles/profile_impl.cc
@@ -84,6 +84,7 @@
 #include "chrome/common/pref_names.h"
 #include "chrome/common/url_constants.h"
 #include "content/public/browser/browser_thread.h"
+#include "content/public/browser/dom_storage_context.h"
 #include "content/public/browser/host_zoom_map.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/render_process_host.h"
@@ -313,6 +314,11 @@ ProfileImpl::ProfileImpl(const FilePath& path,
   } else {
     NOTREACHED();
   }
+
+  if (command_line->HasSwitch(switches::kEnableRestoreSessionState)) {
+    content::BrowserContext::GetDefaultDOMStorageContext(this)->
+        SetSaveSessionStorageOnDisk();
+  }
 }
 
 void ProfileImpl::DoFinalInit(bool is_new_profile) {