Enable YouCompleteMe and :CrCompile to find GN build directory

tools/vim/tests/chromium.ycm_extra_conf_unittest.py

 #!/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.
 
 """Tests for chromium.ycm_extra_conf.
 
 These tests should be getting picked up by the PRESUBMIT.py in /tools/vim.
 Currently the tests only run on Linux and require 'ninja' to be available on
@@ skipping 62 matching lines @@
       |  .gclient
       |
       +-- src
       |   |  DEPS
       |   |  three.cc
       |   |
       |   +-- .git
       |
       +-- out
           |
-          +-- Debug
+          +-- gn
                 build.ninja
     """
     self.chrome_root = os.path.abspath(os.path.normpath(
         os.path.join(self.test_root, 'src')))
-    self.out_dir = os.path.join(self.chrome_root, 'out', 'Debug')
+    self.out_dir = os.path.join(self.chrome_root, 'out', 'gn')
 
     os.makedirs(self.chrome_root)
     os.makedirs(os.path.join(self.chrome_root, '.git'))
     os.makedirs(self.out_dir)
 
     CreateFile(os.path.join(self.test_root, '.gclient'))
     CreateFile(os.path.join(self.chrome_root, 'DEPS'))
     CreateFile(os.path.join(self.chrome_root, 'three.cc'))
 
     # Fake ninja build file. Applications of 'cxx' rule are tagged by which
@@ skipping 59 matching lines @@
         '-I[SRC]',
         '-Wno-unknown-warning-option',
         '-I[OUT]/a',
         '-isysroot',
         '/mac.sdk',
         '-I[OUT]/tag-one'
         ])
 
   def testOutDirNames(self):
     out_root = os.path.join(self.chrome_root, 'out_with_underscore')
-    out_dir = os.path.join(out_root, 'Debug')
+    out_dir = os.path.join(out_root, 'gn')
     shutil.move(os.path.join(self.chrome_root, 'out'),
         out_root)
 
     clang_options = \
         self.ycm_extra_conf.GetClangOptionsFromNinjaForFilename(
             self.chrome_root, os.path.join(self.chrome_root, 'one.cpp'))
     self.assertIn('-I%s/a' % out_dir, clang_options)
     self.assertIn('-I%s/tag-one' % out_dir, clang_options)
 
   def testGetFlagsForFileForKnownCppFile(self):
@@ skipping 151 matching lines @@
         '-DUSE_CLANG_COMPLETER',
         '-std=c++11',
         '-x', 'c++',
         '-I[SRC]',
         '-Wno-unknown-warning-option',
         '-I[OUT]/a',
         '--sysroot=[SRC]/build/sysroot-image',
         ])
 
 if __name__ == '__main__':
+  if not os.path.isfile('chromium.ycm_extra_conf.py'):
+    print('The test must be run from src/tools/vim/ directory')
+    sys.exit(1)
   unittest.main()