handle preload tab when max count is reached

       Bug: 5066968
       when opening the pre-load tab, check against max count
       if max count is already reached, replace the least
       used tab with the pre-loaded tab; it's back/forward
       history will be lost

Change-Id: I091b6b066a3e990f330be458d4aff72f62c8de38
2 files changed