Refactor WebApkServiceConnectionManager.

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 org.chromium.base.ApplicationState;
+import org.chromium.base.ApplicationStatus;
+import org.chromium.base.ContextUtils;
 import org.chromium.base.library_loader.LibraryLoader;
+import org.chromium.webapk.lib.client.WebApkIdentityServiceClient;
 import org.chromium.webapk.lib.client.WebApkValidator;
 
 /**
  * Contains functionality needed for Chrome to host WebAPKs.
  */
 public class ChromeWebApkHost {
     private static final String TAG = "ChromeWebApkHost";
+    private static ApplicationStatus.ApplicationStateListener sListener;
 
     public static void init() {
         WebApkValidator.init(
                 ChromeWebApkHostSignature.EXPECTED_SIGNATURE, ChromeWebApkHostSignature.PUBLIC_KEY);
     }
 
     /* Returns whether launching renderer in WebAPK process is enabled by Chrome. */
     public static boolean canLaunchRendererInWebApkProcess() {
         return LibraryLoader.isInitialized() && nativeCanLaunchRendererInWebApkProcess();
     }
 
+    /** Checks whether Chrome is the runtime host of the WebAPK asynchronously. */
+    public static void checkChromeBacksWebApkAsync(Context appContext, String webApkPackageName,
+            WebApkIdentityServiceClient.CheckBacksWebApkCallback callback) {

[pkotwicz, 2017/07/19 16:09:13]

Does the context have to be passed in?

[Xi Han, 2017/07/21 20:36:33]

Done.

+        maybeRegisterListenerForWebApkIdentityServiceClient();
+        WebApkIdentityServiceClient.checkBacksWebApkAsync(appContext, webApkPackageName, callback);
+    }
+
+    /**
+     * Registers an application listener to disconnect the singleton WebApkIdentityServiceClient if
+     * it hasn't registered yet.
+     */

[pkotwicz, 2017/07/19 16:09:13]

The comment is out of date. Perhaps:
"to disconnect singleton WebApkIdentityserviceClient if it hasn't registered
yet" -> "to disconnect all connections to WebAPKs when Chrome is stopped."

[Xi Han, 2017/07/21 20:36:33]

Thanks!

+    private static void maybeRegisterListenerForWebApkIdentityServiceClient() {
+        if (sListener != null) return;
+
+        sListener = new ApplicationStatus.ApplicationStateListener() {
+            @Override
+            public void onApplicationStateChange(int newState) {
+                if (newState == ApplicationState.HAS_STOPPED_ACTIVITIES
+                        || newState == ApplicationState.HAS_DESTROYED_ACTIVITIES) {
+                    WebApkIdentityServiceClient.disconnectWebApkIdentityService(
+                            ContextUtils.getApplicationContext());
+                    WebApkServiceClient.disconnectWebApkService(
+                            ContextUtils.getApplicationContext());

[pkotwicz, 2017/07/19 16:09:13]

I think that disconnecting from both the WebApkIdentityServiceClient and the
WebApkServiceClient is a lot nicer. Thank you for making the change!

[Xi Han, 2017/07/21 20:36:33]

Acknowledged.

+
+                    ApplicationStatus.unregisterApplicationStateListener(sListener);
+                    sListener = null;
+                }
+            }
+        };
+        ApplicationStatus.registerApplicationStateListener(sListener);
+    }
 
     private static native boolean nativeCanLaunchRendererInWebApkProcess();
 }