Move //webapk to //chrome/android/webapk

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.ComponentName;
 import android.content.Intent;
 import android.content.pm.ApplicationInfo;
@@ skipping 102 matching lines @@
      * @return Whether the url is valid.
      */
     private static boolean isUrlValid(String url) {
         if (url == null) {
             return false;
         }
 
         return url.startsWith("http:") || url.startsWith("https:");
     }
 }