Omnibox UI Experiments: Enable trimming of trivial subdomains.

components/omnibox/browser/autocomplete_match.cc

Index: components/omnibox/browser/autocomplete_match.cc
diff --git a/components/omnibox/browser/autocomplete_match.cc b/components/omnibox/browser/autocomplete_match.cc
index dd0eaf01265b6dce6010bbc47f060bcefefea2a8..3f0e0c8159f897da807777e0f00b563a6add60e3 100644
--- a/components/omnibox/browser/autocomplete_match.cc
+++ b/components/omnibox/browser/autocomplete_match.cc
@@ -526,11 +526,22 @@ base::string16 AutocompleteMatch::FormatUrlForSuggestionDisplayWithAdjustments(
     const GURL& url,
     bool trim_scheme,
     base::OffsetAdjuster::Adjustments* adjustments) {
+  GURL trimmed_url = url;
+
+  // Trim off trivial subdomains if experiment is enabled.
+  if (base::FeatureList::IsEnabled(
+          omnibox::kUIExperimentHideSuggestionUrlTrivialSubdomains)) {
+    GURL::Replacements replacements;
+    replacements.SetHostStr(url_formatter::StripSubdomains(
+        url, url_formatter::kStripWWW | url_formatter::kStripM));
+    trimmed_url = url.ReplaceComponents(replacements);
+  }

[tommycli, 2017/06/23 00:10:54]

This pattern now makes me feel that the smart thing to do for scheme trimming is
basically: if (trim_scheme and feature enabled and scheme is HTTPS) replace
scheme with HTTP and allow url_formatter to trim that off.

If you agree I can followup and do that...

[Justin Donnelly, 2017/06/23 15:12:25]

That's both an elegant solution to the code duplication and also feels like a
weird hack. :) I'm inclined to stick with what you have here and just do the
right thing (put it in url_formatter and/or refactor as pkasting suggested) if
and when we decide it's permanent.

[tommycli, 2017/06/23 18:23:05]

Gotcha, alright good to hear my first instinct was the correct one then. :)

+
   const url_formatter::FormatUrlTypes format_types =
       url_formatter::kFormatUrlOmitAll &
       ~(trim_scheme ? 0 : url_formatter::kFormatUrlOmitHTTP);
   base::string16 result = url_formatter::FormatUrlWithAdjustments(
-      url, format_types, net::UnescapeRule::SPACES, nullptr, nullptr,
+      trimmed_url, format_types, net::UnescapeRule::SPACES, nullptr, nullptr,
       adjustments);
 
   // Also trim HTTPS if experiment is enabled. Note this intentionally has