GCAPI should append to the existing experiment_labels instead of clobbering them.

chrome/chrome_tests_unit.gypi

Index: chrome/chrome_tests_unit.gypi
diff --git a/chrome/chrome_tests_unit.gypi b/chrome/chrome_tests_unit.gypi
index 6b5f43f6cefcdbd280c6f04540213e6ba8bf19fd..dbf88800c10a91405bb38687d169267c2ff87f56 100644
--- a/chrome/chrome_tests_unit.gypi
+++ b/chrome/chrome_tests_unit.gypi
@@ -1843,6 +1843,7 @@
         'common/metrics/caching_permuted_entropy_provider_unittest.cc',
         'common/metrics/metrics_log_base_unittest.cc',
         'common/metrics/metrics_log_manager_unittest.cc',
+        'common/metrics/variations/experiment_labels_win_unittest.cc',

[Alexei Svitkine (slow), 2013/11/05 23:05:23]

Name this experiment_labels_unittest_win.cc, that way the default gypi suffix
filter will exclude it on other platforms automatically.

[gab, 2013/11/06 16:39:10]

Actually the rule works for this ordering too:
https://code.google.com/p/chromium/codesearch#chromium/src/build/filename_rul...

I tend to think of it as:
_win_unittest.cc is a unitest for a _win.cc file
where as _unittest_win.cc is a win-specific test for a regular .cc file.

[Alexei Svitkine (slow), 2013/11/06 22:45:06]

You're right - it didn't always use to be the case, though.

I checked another place that has this logic - the presubmit file that chooses
which trybots to use for your CL and looks like that one also works with this
format now, so all good:

https://code.google.com/p/chromium/codesearch#chromium/src/PRESUBMIT.py&l=1038

         'common/metrics/variations/variations_util_unittest.cc',
         'common/multi_process_lock_unittest.cc',
         'common/net/url_fixer_upper_unittest.cc',