Introduce a new WebAPK launch action.

chrome/android/webapk/shell_apk/src/org/chromium/webapk/shell_apk/MainActivity.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.webapk.shell_apk;
 
 import android.app.Activity;
 import android.content.ActivityNotFoundException;
 import android.content.Context;
 import android.content.Intent;
@@ skipping 20 matching lines @@
     private static final String LAST_RESORT_HOST_BROWSER = "com.android.chrome";
     private static final String LAST_RESORT_HOST_BROWSER_APPLICATION_NAME = "Google Chrome";
     private static final String TAG = "cr_MainActivity";
 
     /**
      * Name of class which launches browser in WebAPK mode.
      */
     private static final String HOST_BROWSER_LAUNCHER_CLASS_NAME =
             "org.chromium.webapk.lib.runtime_library.HostBrowserLauncher";
 
-    // Action for launching {@link WebappLauncherActivity}. Must stay in sync with
-    // {@link WebappLauncherActivity#ACTION_START_WEBAPP}.
+    // Action for launching {@link WebappLauncherActivity}.
+    // TODO(hanxi): crbug.com/737556. Replaces this string with the new WebAPK launch action after
+    // it is propagated to all the Chrome's channels.
     public static final String ACTION_START_WEBAPK =
             "com.google.android.apps.chrome.webapps.WebappManager.ACTION_START_WEBAPP";
 
     // Must stay in sync with
     // {@link org.chromium.chrome.browser.ShortcutHelper#REUSE_URL_MATCHING_TAB_ELSE_NEW_TAB}.
     private static final String REUSE_URL_MATCHING_TAB_ELSE_NEW_TAB =
             "REUSE_URL_MATCHING_TAB_ELSE_NEW_TAB";
 
     /**
      * Key for passing app icon id.
@@ skipping 216 matching lines @@
                     @Override
                     public void onConfirmQuit() {
                         finish();
                     }
                 };
 
         InstallHostBrowserDialog.show(this, listener, hostUrl, lastResortHostBrowserPackageName,
                 lastResortHostBrowserApplicationName, R.drawable.last_resort_runtime_host_logo);
     }
 }