Add a snapshot of flutter/engine/src/build to our sdk

build/grit_target.gypi

+# Copyright (c) 2011 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 that will have one or more
+# uses of grit_action.gypi. To use this the following variables need to be
+# defined:
+#   grit_out_dir: string: the output directory path
+
+# DO NOT USE THIS FILE. Instead, use qualified includes.
+# TODO: Convert everything to qualified includes, and delete this file,
+# http://crbug.com/401588
+{
+  'conditions': [
+    # If the target is a direct binary, it needs to be able to find the header,
+    # otherwise it probably a supporting target just for grit so the include
+    # dir needs to be set on anything that depends on this action.
+    ['_type=="executable" or _type=="shared_library" or \
+      _type=="loadable_module" or _type=="static_library"', {
+      'include_dirs': [
+        '<(grit_out_dir)',
+      ],
+    }, {
+      'direct_dependent_settings': {
+        'include_dirs': [
+          '<(grit_out_dir)',
+        ],
+      },
+    }],
+  ],
+}