gyp_chromium: Better parsing of -G command line flag.

Handle -G output_dir=foo as well as -Goutput_dir=foo.
I'm not sure how common this case is but we have
NaCl SDK bot that do this.

Getting this wrong results in windows toolchain being
installed in 'out/' (which doesn't necessarily exist)
rather than the output_dir tree and gyp uses.

Add unittests for the affected parts of gyp_chromium.

BUG=454594

Review URL: https://codereview.chromium.org/896663002

Cr-Commit-Position: refs/heads/master@{#314381}


CrOS-Libchrome-Original-Commit: 10ef1e2aa8ebb806ccfe7c52235f0fb76564ee2c
diff --git a/build/gyp_chromium_test.py b/build/gyp_chromium_test.py
new file mode 100755
index 0000000..0c0e479
--- /dev/null
+++ b/build/gyp_chromium_test.py
@@ -0,0 +1,66 @@
+#!/usr/bin/env python
+# Copyright 2015 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
+import sys
+import unittest
+
+SCRIPT_DIR = os.path.abspath(os.path.dirname(__file__))
+SRC_DIR = os.path.dirname(SCRIPT_DIR)
+
+sys.path.append(os.path.join(SRC_DIR, 'third_party', 'pymock'))
+
+import mock
+
+# TODO(sbc): Make gyp_chromium more testable by putting the code in
+# a .py file.
+gyp_chromium = __import__('gyp_chromium')
+
+
+class TestGetOutputDirectory(unittest.TestCase):
+  @mock.patch('os.environ', {})
+  @mock.patch('sys.argv', [__file__])
+  def testDefaultValue(self):
+    self.assertEqual(gyp_chromium.GetOutputDirectory(), 'out')
+
+  @mock.patch('os.environ', {'GYP_GENERATOR_FLAGS': 'output_dir=envfoo'})
+  @mock.patch('sys.argv', [__file__])
+  def testEnvironment(self):
+    self.assertEqual(gyp_chromium.GetOutputDirectory(), 'envfoo')
+
+  @mock.patch('os.environ', {'GYP_GENERATOR_FLAGS': 'output_dir=envfoo'})
+  @mock.patch('sys.argv', [__file__, '-Goutput_dir=cmdfoo'])
+  def testGFlagOverridesEnv(self):
+    self.assertEqual(gyp_chromium.GetOutputDirectory(), 'cmdfoo')
+
+  @mock.patch('os.environ', {})
+  @mock.patch('sys.argv', [__file__, '-G', 'output_dir=foo'])
+  def testGFlagWithSpace(self):
+    self.assertEqual(gyp_chromium.GetOutputDirectory(), 'foo')
+
+
+class TestGetGypVars(unittest.TestCase):
+  @mock.patch('os.environ', {})
+  def testDefault(self):
+    self.assertEqual(gyp_chromium.GetGypVars([]), {})
+
+  @mock.patch('os.environ', {})
+  @mock.patch('sys.argv', [__file__, '-D', 'foo=bar'])
+  def testDFlags(self):
+    self.assertEqual(gyp_chromium.GetGypVars([]), {'foo': 'bar'})
+
+  @mock.patch('os.environ', {})
+  @mock.patch('sys.argv', [__file__, '-D', 'foo'])
+  def testDFlagsNoValue(self):
+    self.assertEqual(gyp_chromium.GetGypVars([]), {'foo': '1'})
+
+  @mock.patch('os.environ', {})
+  @mock.patch('sys.argv', [__file__, '-D', 'foo=bar', '-Dbaz'])
+  def testDFlagMulti(self):
+    self.assertEqual(gyp_chromium.GetGypVars([]), {'foo': 'bar', 'baz': '1'})
+
+
+if __name__ == '__main__':
+  unittest.main()