Fix the YCM tests on Mac.

tools/vim/tests/chromium.ycm_extra_conf_unittest.py

Index: tools/vim/tests/chromium.ycm_extra_conf_unittest.py
diff --git a/tools/vim/tests/chromium.ycm_extra_conf_unittest.py b/tools/vim/tests/chromium.ycm_extra_conf_unittest.py
index bb3dca421b8c3a05a66e9ae62d2d971ddc1a8e36..bfaf8fae7435b0a1e7df592a9a369372ce41bfd0 100755
--- a/tools/vim/tests/chromium.ycm_extra_conf_unittest.py
+++ b/tools/vim/tests/chromium.ycm_extra_conf_unittest.py
@@ -74,8 +74,7 @@ class Chromium_ycmExtraConfTest(unittest.TestCase):
           +-- gn
                 build.ninja
     """
-    self.chrome_root = os.path.abspath(os.path.normpath(
-        os.path.join(self.test_root, 'src')))
+    self.chrome_root = os.path.join(self.test_root, 'src')
     self.out_dir = os.path.join(self.chrome_root, 'out', 'gn')
 
     os.makedirs(self.chrome_root)
@@ -108,7 +107,7 @@ class Chromium_ycmExtraConfTest(unittest.TestCase):
                                        'tests', 'data')
     self.ycm_extra_conf = imp.load_source('ycm_extra_conf',
                                           'chromium.ycm_extra_conf.py')
-    self.test_root = tempfile.mkdtemp()
+    self.test_root = os.path.realpath(tempfile.mkdtemp())

[asanka, 2016/09/02 15:05:13]

Shall we avoid calling realpath() here and try to get rid of .relpath() uses
elsewhere? I think we could end up masking similar bugs if we call realpath()
here. Optionally I'd suggest explicitly setting things up so that self.test_root
contains a symlink somewhere so that we can smoke out similar issues.

[Sidney San Martín, 2016/09/09 14:55:49]

I like it :). See the latest patch set — some uses of relpath are useful, like
getting the path of a file relative to the out dir, but it turns out that
realpath was *not* useful.

     self.SetUpFakeChromeTreeBelowPath()
 
   def tearDown(self):