Chrome talks to Play to install WebAPKs.

chrome/android/java/src/org/chromium/chrome/browser/webapps/ChromeWebApkHost.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.content.Context;
 import android.content.DialogInterface;
 import android.content.Intent;
 import android.os.StrictMode;
 import android.provider.Settings;
 import android.support.v7.app.AlertDialog;
+import android.text.TextUtils;
 
 import org.chromium.base.CommandLine;
 import org.chromium.base.ContextUtils;
 import org.chromium.base.Log;
 import org.chromium.base.annotations.CalledByNative;
 import org.chromium.chrome.R;
 import org.chromium.chrome.browser.ChromeFeatureList;
 import org.chromium.chrome.browser.ChromeSwitches;
 import org.chromium.chrome.browser.ChromeVersionInfo;
 import org.chromium.chrome.browser.preferences.ChromePreferenceManager;
+import org.chromium.components.variations.VariationsAssociatedData;
 import org.chromium.webapk.lib.client.WebApkValidator;
 
 /**
  * Contains functionality needed for Chrome to host WebAPKs.
  */
 public class ChromeWebApkHost {
+    /** Flag to enable installing WebAPKs using Google Play. */
+    private static final String PLAY_INSTALL = "play_install";
+
     private static final String TAG = "ChromeWebApkHost";
 
     private static Boolean sEnabledForTesting;
 
     public static void init() {
         WebApkValidator.initWithBrowserHostSignature(ChromeWebApkHostSignature.EXPECTED_SIGNATURE);
     }
 
     public static void initForTesting(boolean enabled) {
         sEnabledForTesting = enabled;
     }
 
     public static boolean isEnabled() {
         if (sEnabledForTesting != null) return sEnabledForTesting;
 
         return isEnabledInPrefs();
     }
 
+    /** Return whether installing WebAPKs using Google Play is enabled. */
+    public static boolean canUseGooglePlayToInstallWebApk() {
+        if (!isEnabled()) return false;
+        return TextUtils.equals(VariationsAssociatedData.getVariationParamValue(
+                ChromeFeatureList.WEBAPKS, PLAY_INSTALL), "true");
+    }
+
     @CalledByNative
     private static boolean areWebApkEnabled() {
         return ChromeWebApkHost.isEnabled();
     }
 
     /**
-     * Check the cached value to figure out if the feature is enabled. We have
-     * to use the cached value because native library may not yet been loaded.
-     *
+     * Check the cached value to figure out if the feature is enabled. We have to use the cached
+     * value because native library may not yet been loaded.
      * @return Whether the feature is enabled.
      */
     private static boolean isEnabledInPrefs() {
         // Will go away once the feature is enabled for everyone by default.
         StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskReads();
         try {
             return ChromePreferenceManager.getInstance(
                     ContextUtils.getApplicationContext()).getCachedWebApkRuntimeEnabled();
         } finally {
             StrictMode.setThreadPolicy(oldPolicy);
@@ skipping 88 matching lines @@
                     }
                 });
         builder.setNegativeButton(android.R.string.cancel, new DialogInterface.OnClickListener() {
             @Override
             public void onClick(DialogInterface dialog, int id) {}
         });
         AlertDialog dialog = builder.create();
         dialog.show();
     }
 }