Add Trending Queries option to On-Focus Suggestions

This change introduces an option to enable query trends in the Omnibox.

Bug: 1122669
Change-Id: I4c5efe7adf2073c7122f65202890a52b4bf58791
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2433145Reviewed-by: Ted Choc <tedchoc@chromium.org>
Commit-Queue: Tomasz Wiszkowski <ender@google.com>
Cr-Commit-Position: refs/heads/master@{#811304}

chrome/browser/about_flags.cc

@@ -1203,6 +1203,8 @@ const FeatureEntry::FeatureVariation kOmniboxOnFocusSuggestionsVariations[] = {
      base::size(kOmniboxNTPZPSRemoteLocal), /* variation_id */ "t3317569"},
     {"Contextual Web", kOmniboxNTPZPSRemoteLocal,
      base::size(kOmniboxNTPZPSRemoteLocal), /* variation_id */ "t3317605"},
+    {"Trending Queries", kOmniboxNTPZPSRemoteLocal,
+     base::size(kOmniboxNTPZPSRemoteLocal), /* variation_id */ "t3317858"},
 #else   // !defined(OS_ANDROID)
     {"NTP Omnibox - Remote History, Local History", kNTPOmniboxZPSRemoteLocal,
      base::size(kNTPOmniboxZPSRemoteLocal), nullptr /* variation_id */},