🏠 Add expand button and flag to enable it

chrome/android/java/src/org/chromium/chrome/browser/ChromeFeatureList.java

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.chrome.browser;
 
 import org.chromium.base.VisibleForTesting;
 import org.chromium.base.annotations.JNINamespace;
 import org.chromium.base.annotations.MainDex;
 import org.chromium.base.library_loader.LibraryLoader;
@@ skipping 132 matching lines @@
 
     // Alphabetical:
     public static final String ANDROID_PAY_INTEGRATION_V1 = "AndroidPayIntegrationV1";
     public static final String ANDROID_PAY_INTEGRATION_V2 = "AndroidPayIntegrationV2";
     public static final String ANDROID_PAYMENT_APPS = "AndroidPaymentApps";
     public static final String AUTOFILL_SCAN_CARDHOLDER_NAME = "AutofillScanCardholderName";
     public static final String CCT_BACKGROUND_TAB = "CCTBackgroundTab";
     public static final String CCT_EXTERNAL_LINK_HANDLING = "CCTExternalLinkHandling";
     public static final String CCT_POST_MESSAGE_API = "CCTPostMessageAPI";
     public static final String CHROME_HOME = "ChromeHome";
+    public static final String CHROME_HOME_EXPAND_BUTTON = "ChromeHomeExpandButton";
     public static final String CONSISTENT_OMNIBOX_GEOLOCATION = "ConsistentOmniboxGeolocation";
     public static final String CONTENT_SUGGESTIONS_FAVICONS_FROM_NEW_SERVER =
             "ContentSuggestionsFaviconsFromNewServer";
     public static final String CONTENT_SUGGESTIONS_NOTIFICATIONS =
             "ContentSuggestionsNotifications";
     public static final String CONTENT_SUGGESTIONS_SETTINGS = "ContentSuggestionsSettings";
     public static final String CONTEXTUAL_SEARCH_SINGLE_ACTIONS = "ContextualSearchSingleActions";
     public static final String CONTEXTUAL_SEARCH_URL_ACTIONS = "ContextualSearchUrlActions";
     public static final String COPYLESS_PASTE = "CopylessPaste";
     public static final String CUSTOM_CONTEXT_MENU = "CustomContextMenu";
@@ skipping 33 matching lines @@
     private static native boolean nativeIsEnabled(String featureName);
     private static native String nativeGetFieldTrialParamByFeature(
             String featureName, String paramName);
     private static native int nativeGetFieldTrialParamByFeatureAsInt(
             String featureName, String paramName, int defaultValue);
     private static native double nativeGetFieldTrialParamByFeatureAsDouble(
             String featureName, String paramName, double defaultValue);
     private static native boolean nativeGetFieldTrialParamByFeatureAsBoolean(
             String featureName, String paramName, boolean defaultValue);
 }