Upstream: Create WebAPK when user selects "Add to Home screen"

chrome/android/java/src/org/chromium/chrome/browser/webapps/WebApkBuilder.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.chrome.browser.webapps;
+
+import android.graphics.Bitmap;
+
+/**
+ * Interface for building WebAPKs.
+ */
+public interface WebApkBuilder {
+    /**
+     * Asynchronously build WebAPK.
+     * @param startUrl The url that the WebAPK should navigate to when launched from the app list.
+     * @param scope Navigations from the WebAPK to URLs with sub-origin {@link scope} will stay
+     *               within the WebAPK.
+     * @param appName Name for the app list.
+     * @param icon Icon for the app list.
+     */
+    void buildWebApkAsync(String startUrl, String scope, String appName, Bitmap appIcon);
+}