sw unit test: add call to CalcLayout before using the layout

Change-Id: Ibb3f8175729cb579a687275a11884c397152fe94
Reviewed-on: https://gerrit.libreoffice.org/1645Reviewed-by: Noel Power <noel.power@suse.com>
Tested-by: Noel Power <noel.power@suse.com>

sw/qa/extras/inc/swmodeltestbase.hxx

@@ -88,6 +88,7 @@ private:
         // create the dump
         SwXTextDocument* pTxtDoc = dynamic_cast<SwXTextDocument *>(mxComponent.get());
         SwDoc* pDoc = pTxtDoc->GetDocShell()->GetDoc();
+        pDoc->GetCurrentViewShell()->CalcLayout();
         SwRootFrm* pLayout = pDoc->GetCurrentLayout();
         pLayout->dumpAsXml(pXmlWriter);