Local NTP, Realbox: show suggestion removal UI only if omnibox does

Conjoins omnibox's transparency UI and the NTP realbox's removal UI on
omnibox::kOmniboxSuggestionTransparencyOptions.

Note: this leaves the keyboard shortcut (Shift+Delete) intentionally
enabled, as this is what Omnibox does.

R=mahmadi@chromium.org

Bug: 1002689
Change-Id: Iffdbd7a94567fce3352c0b7611229f9ddb4846b5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1861275Reviewed-by: Moe Ahmadi <mahmadi@chromium.org>
Commit-Queue: Dan Beam <dbeam@chromium.org>
Auto-Submit: Dan Beam <dbeam@chromium.org>
Cr-Commit-Position: refs/heads/master@{#705813}

chrome/browser/resources/local_ntp/externs.js

@@ -32,6 +32,7 @@ let MostVisitedData;
  *            isGooglePage: boolean,
  *            realboxEnabled: boolean,
  *            richerPicker: boolean,
+ *            suggestionTransparencyEnabled: boolean,
  *            translatedStrings: Object<string>}}
  */
 let configData;

chrome/browser/resources/local_ntp/local_ntp.js

@@ -1462,7 +1462,7 @@ function populateAutocompleteMatches(matches) {
       col.forEach(colEl => matchEl.appendChild(colEl));
     }
 
-    if (match.supportsDeletion) {
+    if (match.supportsDeletion && configData.suggestionTransparencyEnabled) {
       const icon = document.createElement('button');
       icon.title = configData.translatedStrings.removeSuggestion;
       icon.classList.add(CLASSES.REMOVE_ICON);

chrome/browser/search/local_ntp_source.cc

@@ -619,6 +619,10 @@ class LocalNtpSource::SearchConfigurationProvider
                              base::FeatureList::IsEnabled(
                                  features::kChromeColorsCustomColorPicker));
       config_data.SetBoolean("realboxEnabled", features::IsNtpRealboxEnabled());
+      config_data.SetBoolean(
+          "suggestionTransparencyEnabled",
+          base::FeatureList::IsEnabled(
+              omnibox::kOmniboxSuggestionTransparencyOptions));
     }
 
     // Serialize the dictionary.

chrome/test/data/local_ntp/realbox_browsertest.js

@@ -100,6 +100,7 @@ test.realbox.setUp = function() {
   setUpPage('local-ntp-template');
 
   configData.realboxEnabled = true;
+  configData.suggestionTransparencyEnabled = true;
 
   chrome.embeddedSearch = {
     newTabPage: {},