[TTS] Add a Feature and about:flag for Single Actions.

chrome/browser/android/chrome_feature_list.h

Index: chrome/browser/android/chrome_feature_list.h
diff --git a/chrome/browser/android/chrome_feature_list.h b/chrome/browser/android/chrome_feature_list.h
index 9c68a9a35d8350bf0e0c7cd2546cce8dddfd18ec..a7ae673d62b0e30502118a4e7e3025929da87a41 100644
--- a/chrome/browser/android/chrome_feature_list.h
+++ b/chrome/browser/android/chrome_feature_list.h
@@ -12,8 +12,11 @@
 namespace chrome {
 namespace android {
 
+// Alphabetical:
 extern const base::Feature kAndroidPayIntegrationV1;
+extern const base::Feature kCCTExternalLinkHandling;
 extern const base::Feature kChromeHomeFeature;
+extern const base::Feature kContextualSearchSingleActions;
 extern const base::Feature kDownloadsUiFeature;
 extern const base::Feature kImportantSitesInCBD;
 extern const base::Feature kNTPOfflinePagesFeature;
@@ -24,7 +27,6 @@ extern const base::Feature kScanCardsInWebPayments;
 extern const base::Feature kSpecialLocaleFeature;
 extern const base::Feature kSpecialLocaleWrapper;
 extern const base::Feature kTabReparenting;
-extern const base::Feature kCCTExternalLinkHandling;
 extern const base::Feature kUserMediaScreenCapturing;
 
 bool RegisterChromeFeatureListJni(JNIEnv* env);