[Herb] Set up field trial for UI prototypes

chrome/browser/about_flags.cc

Index: chrome/browser/about_flags.cc
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index 2a7e586fe6e6b219a45481a284bf11b73eec8346..0d40805d0b33cf4ee3b02a3204a4d783a672fc39 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -528,7 +528,9 @@ const FeatureEntry::Choice kEnableOfflinePagesChoices[] = {
 };
 
 const FeatureEntry::Choice kHerbPrototypeChoices[] = {
-    {IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED, "", ""},
+    {IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", ""},
+    {IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
+     switches::kTabManagementExperimentType, "disabled"},

[Ted C, 2016/02/22 23:31:21]

I have a sinking suspicion that you need five distinct command lines so you can
use forcing_flag option in your server side configs.

Hopefully someone on the finch side can confirm that for us.

[gone, 2016/02/23 23:57:47]

Talked with Dan (and Alexei over chat), who confirmed that this is necessary.

     {IDS_FLAGS_HERB_PROTOTYPE_FLAVOR_ANISE,
      switches::kTabManagementExperimentType, "anise"},
     {IDS_FLAGS_HERB_PROTOTYPE_FLAVOR_BASIL,