Work on GN toolchain definitions and build

build/toolchain/android/default_goma_for_android.py

Index: build/toolchain/android/default_goma_for_android.py
diff --git a/build/toolchain/android/default_goma_for_android.py b/build/toolchain/android/default_goma_for_android.py
new file mode 100644
index 0000000000000000000000000000000000000000..f84246e4c41f6f9645330e2da3adfa4c6a3bb83f
--- /dev/null
+++ b/build/toolchain/android/default_goma_for_android.py
@@ -0,0 +1,17 @@
+# Copyright 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 script just returns the environment variable GOMA_DIR if there is one,
+# which is the default goma location on Android. Returns the empty string if
+# it's not defined.
+#
+# TODO(brettw) this should be rationalized with the way that other systems get
+# their goma setup.
+
+import os
+
+if 'GOMA_DIR' in os.environ:
+  print '"' + os.environ['GOMA_DIR'] + '"'
+else:
+  print '""'