Add yasm to the GN build

build/gn_run_binary.py

+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Helper script for GN to run an arbitrary binary. See compiled_action.gni.
+
+Run with:
+  python gn_run_binary.py <binary_name> [args ...]
+"""
+
+import sys
+import subprocess
+
+# This script is designed to run binaries produced by the current build. We
+# always prefix it with "./" to avoid picking up system versions that might
+# also be on the path.
+path = './' + sys.argv[1]
+
+# The rest of the arguements are passed directly to the executable.
+args = [path] + sys.argv[2:]
+
+sys.exit(subprocess.call(args))