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

build/ios/PRESUBMIT.py

Index: build/ios/PRESUBMIT.py
diff --git a/build/ios/PRESUBMIT.py b/build/ios/PRESUBMIT.py
new file mode 100644
index 0000000000000000000000000000000000000000..bbd17b3b1d2b4bd3cf844a7751a02e30247df091
--- /dev/null
+++ b/build/ios/PRESUBMIT.py
@@ -0,0 +1,42 @@
+# Copyright (c) 2012 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.
+
+import os
+
+"""Chromium presubmit script for src/tools/ios.
+
+See http://dev.chromium.org/developers/how-tos/depottools/presubmit-scripts
+for more details on the presubmit API built into depot_tools.
+"""
+
+WHITELIST_FILE = 'build/ios/grit_whitelist.txt'
+
+def _CheckWhitelistSorted(input_api, output_api):
+  for path in input_api.LocalPaths():
+    if WHITELIST_FILE == path:
+      lines = open(os.path.join('../..', WHITELIST_FILE)).readlines()
+      i = 0
+      while i < len(lines) - 1 and lines[i] <= lines[i + 1]:
+        i += 1
+      if i < len(lines) - 1:
+        return [output_api.PresubmitError(
+            'The file ' + WHITELIST_FILE + ' must be sorted.  ' +
+            'First offending line: #' + str(i + 2))]
+  return []
+
+def _CommonChecks(input_api, output_api):
+  """Checks common to both upload and commit."""
+  results = []
+  results.extend(_CheckWhitelistSorted(input_api, output_api))
+  return results
+
+def CheckChangeOnUpload(input_api, output_api):
+  results = []
+  results.extend(_CommonChecks(input_api, output_api))
+  return results
+
+def CheckChangeOnCommit(input_api, output_api):
+  results = []
+  results.extend(_CommonChecks(input_api, output_api))
+  return results