GYP: Make GYP build deterministic

test/determinism/gyptest-determinism.py

+#!/usr/bin/env python
+
+# Copyright (c) 2015 Google Inc. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""
+Verifies builds are the same even with different PYTHONHASHSEEDs.
+Tests target_short_names and FlattenToList.
+"""
+
+import os
+import sys
+import TestGyp
+
+test = TestGyp.TestGyp()
+if test.format == 'ninja':
+  os.environ["PYTHONHASHSEED"] = "1"
+  test.run_gyp('determinism.gyp')
+  base = open(test.built_file_path('build.ninja')).read()
+
+  for i in range(1,5):
+    os.environ["PYTHONHASHSEED"] = str(i)
+    test.run_gyp('determinism.gyp')
+    contents = open(test.built_file_path('build.ninja')).read()
+    if base != contents:
+      test.fail_test()
+
+  del os.environ["PYTHONHASHSEED"]
+  test.pass_test()