[omnibox] Add a Feature to control whether the keyword button is shown.

This decouples ongoing work to refine the keyword button from our plans
to experiment on button row and Pedals.

Bug: 1046523
Change-Id: I3eddce8880f7473c837f393231e708bd5a07f56f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2343845
Reviewed-by: Orin Jaworski <[email protected]>
Commit-Queue: Justin Donnelly <[email protected]>
Cr-Commit-Position: refs/heads/master@{#797943}
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index c7740b2..3b1e7e6c 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -3769,14 +3769,18 @@
      flag_descriptions::kOmniboxTabSwitchSuggestionsName,
      flag_descriptions::kOmniboxTabSwitchSuggestionsDescription, kOsDesktop,
      FEATURE_VALUE_TYPE(omnibox::kOmniboxTabSwitchSuggestions)},
-    {"omnibox-pedal-suggestions",
-     flag_descriptions::kOmniboxPedalSuggestionsName,
-     flag_descriptions::kOmniboxPedalSuggestionsDescription, kOsDesktop,
-     FEATURE_VALUE_TYPE(omnibox::kOmniboxPedalSuggestions)},
     {"omnibox-suggestion-button-row",
      flag_descriptions::kOmniboxSuggestionButtonRowName,
      flag_descriptions::kOmniboxSuggestionButtonRowDescription, kOsDesktop,
      FEATURE_VALUE_TYPE(omnibox::kOmniboxSuggestionButtonRow)},
+    {"omnibox-pedal-suggestions",
+     flag_descriptions::kOmniboxPedalSuggestionsName,
+     flag_descriptions::kOmniboxPedalSuggestionsDescription, kOsDesktop,
+     FEATURE_VALUE_TYPE(omnibox::kOmniboxPedalSuggestions)},
+    {"omnibox-keyword-search-button",
+     flag_descriptions::kOmniboxKeywordSearchButtonName,
+     flag_descriptions::kOmniboxKeywordSearchButtonDescription, kOsDesktop,
+     FEATURE_VALUE_TYPE(omnibox::kOmniboxKeywordSearchButton)},
     {"omnibox-drive-suggestions",
      flag_descriptions::kOmniboxDriveSuggestionsName,
      flag_descriptions::kOmniboxDriveSuggestionsDescriptions, kOsDesktop,