Add calls to the server to request WebAPK updates.

chrome/android/java/src/org/chromium/chrome/browser/webapps/WebApkActivity.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.Intent;
 
 import org.chromium.base.ContextUtils;
 import org.chromium.base.library_loader.LibraryProcessType;
 import org.chromium.chrome.browser.ChromeApplication;
 import org.chromium.chrome.browser.ShortcutHelper;
 import org.chromium.chrome.browser.externalnav.ExternalNavigationParams;
 import org.chromium.chrome.browser.tab.InterceptNavigationDelegateImpl;
 import org.chromium.chrome.browser.tab.Tab;
 import org.chromium.chrome.browser.tab.TabDelegateFactory;
 import org.chromium.chrome.browser.tab.TabRedirectHandler;
 import org.chromium.components.navigation_interception.NavigationParams;
 import org.chromium.content.browser.ChildProcessCreationParams;
 import org.chromium.content.browser.ScreenOrientationProvider;
 import org.chromium.content_public.browser.LoadUrlParams;
 import org.chromium.ui.base.PageTransition;
 import org.chromium.webapk.lib.client.WebApkServiceConnectionManager;
 
 /**
  * An Activity is designed for WebAPKs (native Android apps) and displays a webapp in a nearly
  * UI-less Chrome.
  */
 public class WebApkActivity extends WebappActivity {
-    /** Detects whether the associated Web Manifest changes. */
-    private ManifestUpgradeDetector mManifestUpgradeDetector = null;
-
+    /** Manages whether to check update for the WebAPK, and starts update check if needed. */
+    private WebApkUpdateManager mUpdateManager;
     @Override
     protected void onNewIntent(Intent intent) {
         super.onNewIntent(intent);
         // We could bring a WebAPK hosted WebappActivity to foreground and navigate it to a
         // different URL. For example, WebAPK "foo" is launched and navigates to
         // "www.foo.com/foo". In Chrome, user clicks a link "www.foo.com/bar" in Google search
         // results. After clicking the link, WebAPK "foo" is brought to foreground, and
         // loads the page of "www.foo.com/bar" at the same time.
         // The extra {@link ShortcutHelper.EXTRA_URL} provides the URL that the WebAPK will
         // navigate to.
@@ skipping 96 matching lines @@
     }
 
     @Override
     protected void initializeChildProcessCreationParams() {
         // TODO(hanxi): crbug.com/611842. Investigates whether this function works for multiple
         // windows or with --site-per-process enabled.
         initializeChildProcessCreationParams(true);
     }
 
     @Override
-    public void finishNativeInitialization() {
-        super.finishNativeInitialization();
+    public void onDeferredStartup() {
+        super.onDeferredStartup();
 
-        // TODO(hanxi): Ask WebApk's update manager whether to check resource updates.
-        if (mManifestUpgradeDetector == null) {
-            mManifestUpgradeDetector =
-                    new ManifestUpgradeDetector(getActivityTab(), mWebappInfo);
-        }
-        mManifestUpgradeDetector.start();
+        mUpdateManager = new WebApkUpdateManager();
+        mUpdateManager.checkIfUpdateNeeded(getActivityTab(), mWebappInfo);

[pkotwicz, 2016/08/11 22:02:43]

Nit: The method name is deceiving. This method not only checks whether an update
is needed but also does the update if it is needed.

Perhaps rename the method to updateIfNeeded() ?

[Xi Han, 2016/08/15 21:38:44]

Done.

     }
 
     @Override
     public void onPause() {
         super.onPause();
         initializeChildProcessCreationParams(false);
     }
 
     /**
      * Initializes {@link ChildProcessCreationParams} as a WebAPK's renderer process if
      * {@link isForWebApk}} is true; as Chrome's child process otherwise.
      * @param isForWebApk: Whether the {@link ChildProcessCreationParams} is initialized as a
      *                     WebAPK renderer process.
      */
     private void initializeChildProcessCreationParams(boolean isForWebApk) {
         ChromeApplication chrome = (ChromeApplication) ContextUtils.getApplicationContext();
         ChildProcessCreationParams params = chrome.getChildProcessCreationParams();
         if (isForWebApk) {
             int extraBindFlag = params == null ? 0 : params.getExtraBindFlags();
             params = new ChildProcessCreationParams(getWebappInfo().webApkPackageName(),
                     extraBindFlag, LibraryProcessType.PROCESS_CHILD);
         }
         ChildProcessCreationParams.set(params);
     }
 
     @Override
     protected void onDestroyInternal() {
-        if (mManifestUpgradeDetector != null) {
-            mManifestUpgradeDetector.destroy();
+        if (mUpdateManager != null) {
+            mUpdateManager.destroy();
         }
         super.onDestroyInternal();
     }
 }