Transform sample_cnt type to int

Duration is seconds from current time, and sample_cnt on
the basis of duration. So sample_cnt always not a int, but
we need sample_cnt as a int type.

Closes-Bug:#1330330

Change-Id: I89e1768523384e24c3a0b8b76f4fa04a123248f9
Merge "Transform sample_cnt type to int"