Reduce the number of cells in each HTTP request from 1000 to 500.
Reduce the number of cells in each HTTP request from 1000 to 500.

BUG=679253

Review-Url: https://codereview.chromium.org/2635453002

luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go