Add GYP support for Chrome's mojo manifest

mojo/public/mojo_application_manifest.gypi

+# Copyright 2016 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.
+
+{
+  'variables': {
+    'variables': {
+      'application_name%': '<(application_name)',
+      'application_type%': '<(application_type)',
+    },
+    'application_type%': '<(application_type)',
+    'application_name%': '<(application_name)',
+    'manifest_collator_script%':
+        '<(DEPTH)/mojo/public/tools/manifest/manifest_collator.py',
+    'source_manifest%': '<(source_manifest)',
+    'conditions': [
+      ['application_type=="mojo"', {
+        'output_manifest%': '<(PRODUCT_DIR)/<(application_name)/manifest.json',
+      }, {
+        'output_manifest%': '<(PRODUCT_DIR)/<(application_name)_manifest.json',
+      }],
+    ],
+  },
+  'actions': [{
+    'action_name': '<(_target_name)_collation',
+    'inputs': [
+      '<(manifest_collator_script)',
+      '<(source_manifest)',
+    ],
+    'outputs': [
+      '<(output_manifest)',
+    ],
+    'action': [
+      'python',
+      '<(manifest_collator_script)',
+      '--application-name', '<(application_name)',
+      '--parent=<(source_manifest)',
+      '--output=<(output_manifest)',
+    ],
+  }],
+}