[osx] Fix UncheckedMalloc() again.

r242238 attempted to expand the CrMallocErrorBreak() support for
UncheckedMalloc() to handle 10.9.  Unfortunately, the ordering of the
condition means that it actually broke things for all versions of OSX.

BUG=243949
TBR=mark@chromium.org

Review URL: https://codereview.chromium.org/121043002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@242508 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 242508