tree 8959389c97579f80caf14808b81465e5a810a552
parent 19a06bccdfafcfaffc8782f3a8c5eff70dc1e362
author Yaowu Xu <yaowu@google.com> 1463587612 -0700
committer Yaowu Xu <yaowu@google.com> 1473447154 -0700

change to use correct type

This commit changes to use uint32_t for cost (always non-negative),
and promote to int64_t before calculation of the savings.

This fixes an integer overflow.

cherry-picked #a3028ddf from aom/master

Change-Id: I71c2580d188cc79d2d8069241d0353cf331b5c83