mac: Use -O2 for clang release builds for now.

mac: Use -O2 for clang release builds for now.

BUG=none
TEST=none


Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=87141

[Nico, 2011-05-27 23:52:22]

Perf results with slightly different flags are better than no results.

[Mark Mentovai, 2011-05-27 23:54:18]

mmmkay, LGTM

[Mark Mentovai, 2011-05-27 23:55:15]

Also, it’ll be interesting to compare clang -O2 to clang -O3 at some point (like
when clang -O3 works for us?)

I was planning on doing another gcc-4.2 -O2/-O3 showdown as well, because things
might have changed in our code in the past two years.

[commit-bot: I haz the power, 2011-05-28 02:13:48]

Change committed as 87141