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

chrome/installer/util/google_update_constants.cc

Index: chrome/installer/util/google_update_constants.cc
diff --git a/chrome/installer/util/google_update_constants.cc b/chrome/installer/util/google_update_constants.cc
index 9f516ea5e132767860faa28ad9e7f61f24ca11c5..ef387c51563397d8b3aa538eb9a747da12832e36 100644
--- a/chrome/installer/util/google_update_constants.cc
+++ b/chrome/installer/util/google_update_constants.cc
@@ -9,6 +9,7 @@ namespace google_update {
 const wchar_t kChromeUpgradeCode[] = L"{8A69D345-D564-463C-AFF1-A69D9E530F96}";
 
 const wchar_t kExperimentLabels[] = L"experiment_labels";
+const char16 kExperimentLabelSep[] = L";";

[Alexei Svitkine (slow), 2013/08/30 14:17:19]

Unfortunately, you can't use the L prefix for a string16 literal - since L
corresponds to wchar_t which is 32 bit on some platforms.

Perhaps you can change this to an actual single char16 instead of a string.
Then, you can just use ',' for the value. (Because for ascii chars, its the same
value between a char and a char16).

[gab, 2013/08/30 17:53:11]

That doesn't work either as on Windows char16 can't be set to a non "L" value...

How about using wchar_t, but using WideToUTF16 where this matters (i.e. where
AsciiToUTF16 was previously used anyways..)?

[Alexei Svitkine (slow), 2013/08/30 18:16:11]

I guess a cast of the non-L value to char16 would have worked too, but I'm okay
with this solution as well, mostly because those functions are only used on
Windows where WideToUTF16 is a no-op. (On other platforms all those functions
will be dead-stripped from the binary since they're not used.)

[gab, 2013/08/30 22:57:14]

Pulled those functions out to a Windows specific file.

[Alexei Svitkine (slow), 2013/09/03 15:46:35]

I prefer the Windows specific file actually be renamed to
experiment_labels_win.cc with its own unittest file
(experiment_labels_unittest_win.cc).

[gab, 2013/11/05 22:20:38]

Done.

 
 const wchar_t kGoogleUpdateUpgradeCode[] =
     L"{430FD4D0-B729-4F61-AA34-91526481799D}";