Make chrome://flags control whether the WebAPK feature is on

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

 // Copyright 2014 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;
 
 /**
  * Contains all of the command line switches that are specific to the chrome/
  * portion of Chromium on Android.
  */
@@ skipping 178 matching lines @@
 
     public static final String DISABLE_APP_LINK = "disable-app-link";
     public static final String ENABLE_APP_LINK = "enable-app-link";
 
     /**
      * Set the partner-defined homepage URL, for testing.
      */
     public static final String PARTNER_HOMEPAGE_FOR_TESTING = "partner-homepage-for-testing";
 
     /**
-     * Enables "Add to Home screen" to mint a WebApk.
-     */
-    public static final String ENABLE_WEBAPK = "enable-improved-a2hs";
-
-    /**
      * Forces the WebAPK runtime dex to be extracted each time that Chrome is started.
      */
     public static final String ALWAYS_EXTRACT_WEBAPK_RUNTIME_DEX_ON_STARTUP =
             "always-extract-webapk-dex-on-startup";
 
     /**
      * Forces a check for whether the WebAPK's Web Manifest has changed each time that a WebAPK is
      * launched.
      */
     public static final String CHECK_FOR_WEB_MANIFEST_UPDATE_ON_STARTUP =
             "check-for-web-manifest-update-on-startup";
 
     /** Enable Vr Shell development environment. */
     public static final String ENABLE_VR_SHELL_DEV = "enable-vr-shell-dev";
 
     // Prevent instantiation.
     private ChromeSwitches() {}
 }