Roll src/tools/gyp/ to 29e94a3285ee899d14d5e56a6001682620d3778f.

This reinstates the duplicate basename check, on Mac only.

    $ git log 0bb67471b..29e94a328 --date=short --format='%ad %ae %s'
    2015-05-21 scottmg Avoid lint presubmit error in dump_dependency_json
    2015-05-21 scottmg Update shared_library test after c0cf1f22eb
    2015-05-21 scottmg Revert "Stop checking for duplicate basenames"
    2015-05-14 scottmg Added msvs_application_type_revision for winrt compilation
    2015-05-12 torne Remove the Android generator.

R=thakis@chromium.org
BUG=490824, gyp:384, 472772

Review URL: https://codereview.chromium.org/1152323002

Cr-Original-Commit-Position: refs/heads/master@{#331626}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 013831e64e2ca1414e86fe2498cb193d5a8b8354

gyp_chromium

@@ -261,6 +261,14 @@ if __name__ == '__main__':
   if gyp_vars_dict.get('OS') != 'ios':
     args.append('--no-circular-check')
 
+  # libtool on Mac warns about duplicate basenames in static libraries, so
+  # they're disallowed in general by gyp. We are lax on this point, so disable
+  # this check other than on Mac. GN does not use static libraries as heavily,
+  # so over time this restriction will mostly go away anyway, even on Mac.
+  # https://code.google.com/p/gyp/issues/detail?id=384
+  if sys.platform != 'darwin':
+    args.append('--no-duplicate-basename-check')
+
   # We explicitly don't support the make gyp generator (crbug.com/348686). Be
   # nice and fail here, rather than choking in gyp.
   if re.search(r'(^|,|\s)make($|,|\s)', os.environ.get('GYP_GENERATORS', '')):