Fix SessionStorage confusion between RenderViewHostImpl and NavigationController.

content/browser/web_contents/web_contents_impl.cc

Index: content/browser/web_contents/web_contents_impl.cc
diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
index 941e17ffc97e394e20a68074f6804ebfec4cb4ca..13e3c66b4c9adc552708fbee69d9b14ab6b687ac 100644
--- a/content/browser/web_contents/web_contents_impl.cc
+++ b/content/browser/web_contents/web_contents_impl.cc
@@ -1704,6 +1704,11 @@ void WebContentsImpl::RequestMediaAccessPermission(
     callback.Run(MediaStreamDevices(), scoped_ptr<MediaStreamUI>());
 }
 
+SessionStorageNamespace* WebContentsImpl::GetSessionStorageNamespace(
+    SiteInstance* instance) {
+  return controller_.GetSessionStorageNamespace(instance);
+}
+
 void WebContentsImpl::DidSendScreenRects(RenderWidgetHostImpl* rwh) {
   if (browser_plugin_embedder_)
     browser_plugin_embedder_->DidSendScreenRects();