Use default flag style for multi-value flags if no switches have been passed.

chrome/browser/about_flags.cc

 // Copyright (c) 2012 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.
 
 #include "chrome/browser/about_flags.h"
 
 #include <iterator>
 #include <map>
 #include <set>
 #include <utility>
@@ skipping 2162 matching lines @@
 #endif
   }
 
   std::set<std::string> new_enabled_experiments =
       base::STLSetIntersection<std::set<std::string> >(
           platform_experiments, *result);
 
   result->swap(new_enabled_experiments);
 }
 
+// Returns true if none of this experiment's options have been enabled.
+bool IsDefaultValue(
+    const Experiment& experiment,
+    const std::set<std::string>& enabled_experiments) {
+  switch (experiment.type) {
+    case Experiment::SINGLE_VALUE:
+    case Experiment::SINGLE_DISABLE_VALUE:
+      return enabled_experiments.count(experiment.internal_name) == 0;
+    case Experiment::MULTI_VALUE:
+    case Experiment::ENABLE_DISABLE_VALUE:
+      for (int i = 0; i < experiment.num_choices; ++i) {
+        if (enabled_experiments.count(experiment.NameForChoice(i)) > 0)
+          return false;
+      }
+      break;
+    default:
+      NOTREACHED();
+  }
+  return true;
+}
+
 // Returns the Value representing the choice data in the specified experiment.
 base::Value* CreateChoiceData(
     const Experiment& experiment,
     const std::set<std::string>& enabled_experiments) {
   DCHECK(experiment.type == Experiment::MULTI_VALUE ||
          experiment.type == Experiment::ENABLE_DISABLE_VALUE);
   base::ListValue* result = new base::ListValue;
   for (int i = 0; i < experiment.num_choices; ++i) {
     base::DictionaryValue* value = new base::DictionaryValue;
     const std::string name = experiment.NameForChoice(i);
@@ skipping 88 matching lines @@
     data->SetString("name",
                     l10n_util::GetStringUTF16(experiment.visible_name_id));
     data->SetString("description",
                     l10n_util::GetStringUTF16(
                         experiment.visible_description_id));
 
     base::ListValue* supported_platforms = new base::ListValue();
     AddOsStrings(experiment.supported_platforms, supported_platforms);
     data->Set("supported_platforms", supported_platforms);
     // True if the switch is not currently passed.
-    bool is_default_value =
-        enabled_experiments.count(experiment.internal_name) == 0;
+    bool is_default_value = IsDefaultValue(experiment, enabled_experiments);
+    data->SetBoolean("is_default", is_default_value);
 
     switch (experiment.type) {
       case Experiment::SINGLE_VALUE:
       case Experiment::SINGLE_DISABLE_VALUE:
-        data->SetBoolean("is_default", is_default_value);
-
         data->SetBoolean(
             "enabled",
             (!is_default_value &&
              experiment.type == Experiment::SINGLE_VALUE) ||
             (is_default_value &&
              experiment.type == Experiment::SINGLE_DISABLE_VALUE));
         break;
       case Experiment::MULTI_VALUE:
       case Experiment::ENABLE_DISABLE_VALUE:
         data->Set("choices", CreateChoiceData(experiment, enabled_experiments));
@@ skipping 293 matching lines @@
 }
 
 const Experiment* GetExperiments(size_t* count) {
   *count = num_experiments;
   return experiments;
 }
 
 }  // namespace testing
 
 }  // namespace about_flags