Fix: Prerendering was confusing SessionService to not save sessionStorage.

content/browser/dom_storage/session_storage_namespace_impl.cc

Index: content/browser/dom_storage/session_storage_namespace_impl.cc
diff --git a/content/browser/dom_storage/session_storage_namespace_impl.cc b/content/browser/dom_storage/session_storage_namespace_impl.cc
index cb44e043f93f5e22b5f5a4a460c91d954beb7267..1adc5c280ddb6b58f0adf09230cd8eac72b36475 100644
--- a/content/browser/dom_storage/session_storage_namespace_impl.cc
+++ b/content/browser/dom_storage/session_storage_namespace_impl.cc
@@ -38,6 +38,10 @@ void SessionStorageNamespaceImpl::SetShouldPersist(bool should_persist) {
   session_->SetShouldPersist(should_persist);
 }
 
+bool SessionStorageNamespaceImpl::should_persist() const {
+  return session_->should_persist();
+}
+
 SessionStorageNamespaceImpl* SessionStorageNamespaceImpl::Clone() {
   return new SessionStorageNamespaceImpl(session_->Clone());
 }