b=565186; remove NS_ENSURE_TRUE in nsHtml5TreeOpExecutor; r=hsivonen

parser/html/nsHtml5TreeOpExecutor.cpp

@@ -607,7 +607,8 @@ nsHtml5TreeOpExecutor::FlushDocumentWrite()
 PRBool
 nsHtml5TreeOpExecutor::IsScriptEnabled()
 {
-  NS_ENSURE_TRUE(mDocument && mDocShell, PR_TRUE);
+  if (!mDocument || !mDocShell)
+    return PR_TRUE;
   nsCOMPtr<nsIScriptGlobalObject> globalObject = mDocument->GetScriptGlobalObject();
   // Getting context is tricky if the document hasn't had its
   // GlobalObject set yet