Linux: call download_nacl_irt.py in export_tarball.py

to make sure the generated tarballs can be built with NaCl support.

export_tarball.py is not the prettiest place for this,
but it's the easiest to modify (public repo),
and can easily be kept in sync with other scripts in the tree
in case anything changes.

BUG=none
Review URL: http://codereview.chromium.org/7066022

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@86583 0039d316-1c4b-4281-b951-d872f2087c98

tools/export_tarball/export_tarball.py

@@ -18,6 +18,7 @@ The above will create file /foo/bar.tar.bz2.
 
 import optparse
 import os
+import subprocess
 import sys
 import tarfile
 
@@ -97,6 +98,17 @@ def main(argv):
     print 'Cannot find the src directory.'
     return 1
 
+  nacl_download_path = os.path.join(
+      GetSourceDirectory(), 'build', 'download_nacl_irt.py')
+  nacl_cwd = os.path.join(GetSourceDirectory(), '..')
+  if subprocess.call(['python', nacl_download_path], cwd=nacl_cwd) != 0:
+    # The error is not fatal - NaCl is still experimental.
+    print 'Failed to download NaCl integrated runtime files.'
+    print 'The NaCl-enabled build will fail. You can pass -Ddisable_nacl=1'
+    print 'to gyp as a workaround. For more info see'
+    print ('http://groups.google.com/a/chromium.org/group/chromium-dev/'
+           'browse_thread/thread/1fe6e2c3f9e78c2b')
+
   output_fullname = args[0] + '.tar.bz2'
   output_basename = os.path.basename(args[0])