Fix platform conditionalization of NaCl IRT file name

Recognize ARM vs x86.  Give a build error for other machines, where NaCl
should not be enabled since it hasn't been ported.

BUG= http://code.google.com/p/chromium/issues/detail?id=107883
TEST= nacl_integration

[email protected]

Review URL: http://codereview.chromium.org/8964019

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@114863 0039d316-1c4b-4281-b951-d872f2087c98
1 file changed