Gets mandoline working on android

mojo/generate_mojo_shell_assets_list.gni

+# Copyright 2015 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.
+
+# Used to generate an assets_list file. To use supply the argument 'dir', which
+# is where the assets can be found.
+# TODO(sky): Perhaps combine this with the copy step?
+template("generate_mojo_shell_assets_list") {
+  action(target_name) {
+    script = "//mojo/tools/generate_mojo_shell_assets_list.py"
+    args = [
+      "--dir",
+      rebase_path(invoker.dir, root_build_dir),
+    ]
+    outputs = [
+      invoker.dir + "/assets_list",
+    ]
+    if (defined(invoker.deps)) {
+      deps = invoker.deps
+    }
+  }
+}