Update perf expectations: mac-release/sizes/chrome-si/initializers

BUG=306729
TBR=jochen@chromium.org

Review URL: https://codereview.chromium.org/27091002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@228316 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 228316