Allow overriding variation parameter via chrome://flags.

chrome/browser/about_flags_unittest.cc

Index: chrome/browser/about_flags_unittest.cc
diff --git a/chrome/browser/about_flags_unittest.cc b/chrome/browser/about_flags_unittest.cc
index 416c01fc5be15db784fd15c2ad021f5f81d3ea88..0fbdbd2cf7aa72642793f7c0c78016325d5f6f63 100644
--- a/chrome/browser/about_flags_unittest.cc
+++ b/chrome/browser/about_flags_unittest.cc
@@ -184,8 +184,8 @@ std::set<std::string> GetAllSwitchesForTesting() {
         result.insert(entry.command_line_switch);
         break;
       case flags_ui::FeatureEntry::MULTI_VALUE:
-        for (int j = 0; j < entry.num_choices; ++j) {
-          result.insert(entry.choices[j].command_line_switch);
+        for (int j = 0; j < entry.num_options; ++j) {
+          result.insert(entry.ChoiceForOption(j).command_line_switch);
         }
         break;
       case flags_ui::FeatureEntry::ENABLE_DISABLE_VALUE: