Add support for webapk without runtimeHost

chrome/android/webapk/libs/common/src/org/chromium/webapk/lib/common/WebApkConstants.java

 // Copyright 2016 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.webapk.lib.common;
 
 /**
  * Stores WebAPK related constants.
  */
 public final class WebApkConstants {
     public static final String WEBAPK_PACKAGE_PREFIX = "org.chromium.webapk";
 
     // WebAPK id prefix. The id is used for storing WebAPK data in Chrome's SharedPreferences.
     public static final String WEBAPK_ID_PREFIX = "webapk:";
 
     // These EXTRA_* values must stay in sync with
     // {@link org.chromium.chrome.browser.ShortcutHelper}.
     public static final String EXTRA_URL = "org.chromium.chrome.browser.webapp_url";
     public static final String EXTRA_SOURCE = "org.chromium.chrome.browser.webapp_source";
     public static final String EXTRA_WEBAPK_PACKAGE_NAME =
             "org.chromium.chrome.browser.webapk_package_name";
     // Whether the WebAPK should navigate to the URL in {@link EXTRA_URL} if the WebAPK is already
     // open.
     public static final String EXTRA_WEBAPK_FORCE_NAVIGATION =
             "org.chromium.chrome.browser.webapk_force_navigation";
 
+    public static final String DEFAULT_HOST_BROWSER = "com.android.chrome";
+
     // Must be kept in sync with chrome/browser/android/shortcut_info.h.
     public static final int SHORTCUT_SOURCE_UNKNOWN = 0;
     public static final int SHORTCUT_SOURCE_EXTERNAL_INTENT = 9;
+
+    /** Name of the shared preferences file. */
+    public static final String PREF_PACKAGE = "org.chromium.webapk.shell_apk";
 }