Add support for sysroots to GN's pkg-config.

build/config/linux/sysroot_ld_path.py

Index: build/config/linux/sysroot_ld_path.py
diff --git a/build/config/linux/sysroot_ld_path.py b/build/config/linux/sysroot_ld_path.py
new file mode 100644
index 0000000000000000000000000000000000000000..4bce7ee3e2bff5ca7e7b5c0f3c15a3e50d2c58b8
--- /dev/null
+++ b/build/config/linux/sysroot_ld_path.py
@@ -0,0 +1,20 @@
+# Copyright (c) 2013 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.
+
+# This file takes two arguments, the relative location of the shell script that
+# does the checking, and the name of the sysroot.
+
+# TODO(brettw) the build/linux/sysroot_ld_path.sh script should be rewritten in
+# Python in this file.
+
+import subprocess
+import sys
+
+if len(sys.argv) != 3:
+  print "Need two arguments"
+  sys.exit(1)
+
+result = subprocess.check_output([sys.argv[1], sys.argv[2]]).strip()
+
+print '"' + result + '"'