Result of -float is wrong on Intel Mac 10.11 drivers. Replace -float
with 0.0 - float to work around this issue.

BUG=308366
BUG=672380

Change-Id: I53bc2eda7259fff5805bec39896fc7b7a6eaf665
Reviewed-on: https://chromium-review.googlesource.com/417169Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>