IDL build: factor out interface_info actions into GYP templates

Source/bindings/scripts/interfaces_info_overall.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.
+#
+# This file is meant to be included into a target to provide an action
+# to compute overall information about interfaces defined in a component.
+#
+# To use this, create a gyp target with the following form:
+# {
+#   'target_name': 'interfaces_info_component',
+#   'dependencies': [
+#       'interfaces_info_individual_base_component',
+#       'interfaces_info_individual_component',
+#   ],
+#   'variables': {
+#     'input_files': [
+#       '<(bindings_base_component_output_dir)/InterfacesInfoBaseComponentIndividual.pickle',
+#       '<(bindings_component_output_dir)/InterfacesInfoComponentIndividual.pickle',
+#     ],
+#     'output_file':
+#       '<(bindings_component_output_dir)/InterfacesInfoComponent.pickle',
+#   },
+#   'includes': ['path/to/this/gypi/file'],
+# },
+#
+# Required variables:
+#  input_files - Pickle files containing info about individual interfaces, both
+#    current component and any base components.
+#  output_file - Pickle file containing output (overall info).
+#
+# Design document: http://www.chromium.org/developers/design-documents/idl-build
+
+{
+  'type': 'none',
+  'actions': [{
+    'action_name': 'compute_<(_target_name)',
+    'message': 'Computing overall global information about IDL files for <(_target_name)',
+
+    'inputs': [
+      '<(bindings_scripts_dir)/compute_interfaces_info_overall.py',
+      '<@(input_files)',
+    ],
+    'outputs': [
+      '<(output_file)',
+    ],
+    'action': [
+      'python',
+      '<(bindings_scripts_dir)/compute_interfaces_info_overall.py',
+      '--write-file-only-if-changed',
+      '<(write_file_only_if_changed)',
+      '--',
+      '<@(input_files)',
+      '<(output_file)',
+    ],
+  }],
+}