Persist sessionStorage on disk.

content/browser/dom_storage/dom_storage_context_impl.cc

Index: content/browser/dom_storage/dom_storage_context_impl.cc
diff --git a/content/browser/dom_storage/dom_storage_context_impl.cc b/content/browser/dom_storage/dom_storage_context_impl.cc
index 683e105d7d4587564208ed0abe0bd487c1195c76..e4bdc4e52180973b7b5c1f8ae2ed9544cec02b08 100644
--- a/content/browser/dom_storage/dom_storage_context_impl.cc
+++ b/content/browser/dom_storage/dom_storage_context_impl.cc
@@ -26,6 +26,7 @@ using webkit_database::DatabaseUtil;
 namespace {
 
 const char kLocalStorageDirectory[] = "Local Storage";
+const char kSessionStorageDirectory[] = "Session Storage";
 
 // TODO(michaeln): Fix the content layer api, FilePaths and
 // string16 origin_ids are just wrong. Then get rid of
@@ -86,7 +87,8 @@ DOMStorageContextImpl::DOMStorageContextImpl(
   context_ = new dom_storage::DomStorageContext(
       data_path.empty() ?
           data_path : data_path.AppendASCII(kLocalStorageDirectory),
-      FilePath(),  // Empty session storage directory.
+      data_path.empty() ?
+          data_path : data_path.AppendASCII(kSessionStorageDirectory),
       special_storage_policy,
       new DomStorageWorkerPoolTaskRunner(
           worker_pool,