Add support for "else if" in gyp conditions

test/conditions/elseif/gyptest_elseif.py

+#!/usr/bin/env python
+
+# Copyright (c) 2014 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.
+
+"""
+Verify that "else-if" conditions work.
+"""
+
+import TestGyp
+
+test = TestGyp.TestGyp()
+
+test.run_gyp('elseif.gyp')
+test.build('elseif.gyp', test.ALL)
+test.run_built_executable(
+    'program0', stdout='first_if\n')
+test.run_built_executable(
+    'program1', stdout='first_else_if\n')
+test.run_built_executable(
+    'program2', stdout='second_else_if\n')
+test.run_built_executable(
+    'program3', stdout='third_else_if\n')
+test.run_built_executable(
+    'program4', stdout='last_else\n')
+
+# Verify that bad condition blocks fail at gyp time.
+test.run_gyp('elseif_bad1.gyp', status=1, stderr=None)
+test.run_gyp('elseif_bad2.gyp', status=1, stderr=None)
+test.run_gyp('elseif_bad3.gyp', status=1, stderr=None)
+
+test.pass_test()