I think the problem is in the test itself that uses the SingleResourceLoadTest to load a multiresource document.
Created attachment 167713 [details] Patch I'm unable to reproduce the assertion, so I'm not sure the patch will fix it.
Btw, the assertion is this one: /webkit2/WebKitWebView/history-cache: ASSERTION FAILED: m_loadState == LoadStateCommitted ../../Source/WebKit2/UIProcess/WebFrameProxy.cpp(176) : void WebKit::WebFrameProxy::didFinishLoad()
Thanks for the patch. If this patch contains new public API please make sure it follows the guidelines for new WebKit2 GTK+ API. See http://trac.webkit.org/wiki/WebKitGTK/AddingNewWebKit2API
Committed r130886: <http://trac.webkit.org/changeset/130886>