Bug 1418009 - Avoid speculative connections on prematurely inserted lazy tabs r=dao

MozReview-Commit-ID: 3T8PLBLEGNt

--HG--
extra : rebase_source : 68a9d0702e33bbc4d88d00b3cc1430d445a7562b

browser/components/sessionstore/SessionStore.jsm

@@ -3547,7 +3547,7 @@ var SessionStoreInternal = {
    *        a tab to speculatively connect on mouse hover.
    */
   speculativeConnectOnTabHover(tab) {
-    if (this._restore_on_demand && !tab.__SS_connectionPrepared && tab.hasAttribute("pending")) {
+    if (tab.__SS_lazyData && !tab.__SS_connectionPrepared) {
       let url = this.getLazyTabValue(tab, "url");
       let prepared = this.prepareConnectionToHost(url);
       // This is used to test if a connection has been made beforehand.