Inline extensions .gypi files into GN build.

extensions/shell/common/api/schemas.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.
-
-{
-  'sources': [
-    '<@(schema_files)',
-  ],
-  'variables': {
-    'schema_files': [
-      'identity.idl',
-    ],
-    'non_compiled_schema_files': [
-    ],
-    # Chrome OS specific APIs.
-    'chromeos_schema_files': [
-    ],
-    
-    'chromium_code': 1,
-    'cc_dir': 'extensions/shell/common/api',
-    'root_namespace': 'extensions::shell::api::%(namespace)s',
-    'bundle_name': 'Shell',
-    'impl_dir_': 'extensions/shell/browser/api',
-    
-    'conditions': [
-      ['chromeos==1', {
-        'schema_files': [
-          '<@(chromeos_schema_files)',
-        ],
-      }],
-    ],
-  },
-}