cpu flags of 1 disables SIMD and uses C.  This used to be 0, but the change
in auto init behavior means that 0 now means uninitialized, and will cause
auto detect to reinit the cpu info.  A value of 1 disables the auto init.

TBR=harryjin@google.com
BUG=none

Review URL: https://codereview.chromium.org/1408753004 .