Fix depot_tools unit tests on Windows.

tests/trychange_unittest.py

 #!/usr/bin/python
 # Copyright (c) 2009 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.
 
 """Unit tests for trychange.py."""
 
 import optparse
 import unittest
 
@@ skipping 51 matching lines @@
     self.assertEqual(self.svn.GetFileNames(), self.expected_files)
 
   def testGetLocalRoot(self):
     self.mox.ReplayAll()
     self.assertEqual(self.svn.GetLocalRoot(), self.fake_root)
 
 
 class GITUnittest(TryChangeTestsBase):
   """trychange.GIT tests."""
   def setUp(self):
-    self.fake_root = '/fake_root'
+    self.fake_root = gcl.os.path.join(gcl.os.path.dirname(__file__),
+                                      'fake_root')
     self.expected_files = ['foo.txt', 'bar.txt']
     options = optparse.Values()
     options.files = self.expected_files
     self.git = trychange.GIT(options)
     super_mox.SuperMoxTestBase.setUp(self)
 
   def testMembersChanged(self):
     members = [
       'GenerateDiff', 'GetEmail', 'GetFileNames', 'GetLocalRoot',
       'GetPatchName', 'ProcessOptions', 'options'
     ]
     # If this test fails, you should add the relevant test.
     self.compareMembers(trychange.GIT(None), members)
 
   def testGetFileNames(self):
     self.mox.ReplayAll()
     self.assertEqual(self.git.GetFileNames(), self.expected_files)
 
   def testGetLocalRoot(self):
     self.mox.StubOutWithMock(upload, 'RunShell')
     upload.RunShell(['git', 'rev-parse', '--show-cdup']).AndReturn(
         self.fake_root)
     self.mox.ReplayAll()
     self.assertEqual(self.git.GetLocalRoot(), self.fake_root)
 
 
 if __name__ == '__main__':
   unittest.main()