Add a feature parameter to disable UI for IDN navigation suggestions

This CL adds a "metrics_only" parameter to IdnNavigationSuggestions feature. When set to "true",
the parameter will suppress the display of the "Did you mean to go to ..." UI and only
record metrics.

Bug: 843361,847662
Change-Id: Idb72225ff0fc2f011bd2c1ae5bb0ee7167d687ba
Reviewed-on: https://chromium-review.googlesource.com/1182123
Commit-Queue: Mustafa Emre Acer <[email protected]>
Reviewed-by: Tommy Li <[email protected]>
Cr-Commit-Position: refs/heads/master@{#585360}
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index 91b566d..89bc5f6f 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -485,6 +485,14 @@
 };
 #endif  // OS_CHROMEOS
 
+const FeatureEntry::FeatureParam kIdnNavigationSuggestionsMetricsOnly[] = {
+    {"metrics_only", "true"},
+};
+
+const FeatureEntry::FeatureVariation kIdnNavigationSuggestionVariants[] = {
+    {"With Metrics Only", kIdnNavigationSuggestionsMetricsOnly,
+     base::size(kIdnNavigationSuggestionsMetricsOnly)}};
+
 const FeatureEntry::Choice kExtensionContentVerificationChoices[] = {
     {flags_ui::kGenericExperimentChoiceDefault, "", ""},
     {flag_descriptions::kExtensionContentVerificationBootstrap,
@@ -4288,7 +4296,9 @@
     {"enable-idn-navigation-suggestions",
      flag_descriptions::kIdnNavigationSuggestionsName,
      flag_descriptions::kIdnNavigationSuggestionsDescription, kOsDesktop,
-     FEATURE_VALUE_TYPE(features::kIdnNavigationSuggestions)},
+     FEATURE_WITH_PARAMS_VALUE_TYPE(features::kIdnNavigationSuggestions,
+                                    kIdnNavigationSuggestionVariants,
+                                    "IdnNavigationSuggestions")},
 
 #if defined(OS_ANDROID)
     {"long-press-back-for-history",