Fix default ARCHS value for iOS project.

Xcode 5.0.0 only default to x86_64 when building Mac project, not
iOS projects (since default target of iOS 5.0 does not supports
64-bits binaries).

Patch by Sylvain Defresne <sdefresne@chromium.org>

BUG=chromium:322075
R=thakis@chromium.org

Review URL: https://codereview.chromium.org/81213003

git-svn-id: http://gyp.googlecode.com/svn/trunk@1798 78cadc50-ecff-11dd-a971-7dbc132099af
5 files changed