Provide script/gypi support for manifest generation

chrome/browser/resources/chromeos/chromevox/generate_manifest.gypi

+# 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.
+
+# Generates an output manifest based on a Jinja2 templated manifest.
+# Include this file inside of your target to generate a manifest.
+# The following variables must be set before including this file:

[Peter Lundblad, 2014/05/23 22:37:19]

Mention is_guest_manifest as an optional variable for completeness.

[David Tseng, 2014/05/23 22:57:16]

Done.

+#
+# template_manifest: a valid Jinja2 file path.
+# output_manifest: file path for the resulting manifest.

[Peter Lundblad, 2014/05/23 22:37:19]

Variables naming files commonly end in _file or _path.  The reason for that is
so that
gyp fixes relative paths if the gypi is included from another directory and
it does that for variables with certain suffixes.  Care to rename these two?

[David Tseng, 2014/05/23 22:57:16]

Obscure; thanks and done.

+
+{
+  'actions': [
+    {
+      'action_name': 'generate_manifest',
+      'message': 'Generate manifest for <(_target_name)',
+      'variables': {
+        'is_guest_manifest%': 0,
+      },
+      'inputs': [
+        'tools/generate_manifest.py',
+        '<(template_manifest)',
+      ],
+      'outputs': [
+        '<(output_manifest)'
+      ],
+      'action': [
+        'python',
+        'tools/generate_manifest.py',
+        '-o', '<(output_manifest)',
+        '-g', '<(is_guest_manifest)',
+        '<(template_manifest)'
+      ],
+    },
+  ],
+}