[NaCl SDK] Use chromium trybots when making changes to native_client_sdk.

Also made change to top-level PRESUBMIT.py to prevent testing default bots when
change is only in native_client_sdk.

BUG=none
[email protected]


Review URL: https://chromiumcodereview.appspot.com/10919303

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@157653 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/PRESUBMIT.py b/PRESUBMIT.py
index 9a7a6803..55e56d80 100644
--- a/PRESUBMIT.py
+++ b/PRESUBMIT.py
@@ -607,6 +607,8 @@
     return ['win_rel']
   if all(re.search('(^|[/_])android[/_.]', f) for f in files):
     return ['android_dbg']
+  if all(re.search('^native_client_sdk', f) for f in files):
+    return ['linux_nacl_sdk', 'win_nacl_sdk', 'mac_nacl_sdk']
 
   trybots = ['win_rel', 'linux_rel', 'mac_rel', 'linux_clang:compile',
              'linux_chromeos', 'android_dbg', 'linux_asan', 'mac_asan']