Omit DLOGs and DCHECKs from release-mode Google Chrome-branded builds

Omit DLOGs and DCHECKs from release-mode Google Chrome-branded builds on
non-Windows.  They were previously omitted on Windows official builds only.

BUG=16512
TEST=DCHECK logging unavailable in official builds;
     Mac .app shrinks by about 740kB;
     Mac .dmg shrinks by about 315kB;
     Linux binary and package shrink by similar amounts

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=23791

[Mark Mentovai, 2009-08-18 02:03:05]

We tried this before at r20497 but reverted it at r20889 because it caused
hangs.  See http://crbug.com/16871.

I made it through unit_tests with this change without anything hanging.  I'll
bang on it a little bit more.  If it's still causing problems, I'd like to fix
them and get this in for the beta.

[Mark Mentovai, 2009-08-18 04:14:58]

We're hanging in IPCSyncChannelTest.ChattyServer when the DCHECK_EQ in
LockImpl::Lock, base/lock_impl_posix.cc, is optimized away.

[Mark Mentovai, 2009-08-19 16:23:56]

This depends on http://codereview.chromium.org/173059 and
http://crbug.com/19710.  Other than that, it's ready to go.

[TVL, 2009-08-19 16:28:47]

lgtm