Fix SessionStorage confusion between RenderViewHostImpl and NavigationController.

content/browser/renderer_host/render_view_host_delegate.h

Index: content/browser/renderer_host/render_view_host_delegate.h
diff --git a/content/browser/renderer_host/render_view_host_delegate.h b/content/browser/renderer_host/render_view_host_delegate.h
index f73b0410a3f3a85733976b204b5a710b46930f54..a7f5cc933c5a3297f4c11a9b257543be330a1ac6 100644
--- a/content/browser/renderer_host/render_view_host_delegate.h
+++ b/content/browser/renderer_host/render_view_host_delegate.h
@@ -414,6 +414,10 @@ class CONTENT_EXPORT RenderViewHostDelegate {
       const MediaStreamRequest& request,
       const MediaResponseCallback& callback) {}
 
+  // Returns the SessionStorageNamespace the render view should use. Might
+  // create the SessionStorageNamespace on the fly.
+  virtual SessionStorageNamespace* GetSessionStorageNamespace();
+
  protected:
   virtual ~RenderViewHostDelegate() {}
 };