Update size expectations for mac

We're seeing a 0.08% size regression on Mac release builds. Updating
the expectations to cover that change.

BUG=338077

Review URL: https://codereview.chromium.org/143653013

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@247073 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 247073