A little more test on shared string pool's life cycle management.
A little more test on shared string pool's life cycle management.

Change-Id: Ic676dd875c27ce60a0707903d7f22207764829e0

JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core