Revert of [Reland] Refactor WebappRegistry into a singleton instance.

chrome/android/java/src/org/chromium/chrome/browser/DeferredStartupHandler.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.chrome.browser;
 
 import android.content.Context;
 import android.content.Intent;
 import android.content.SharedPreferences;
 import android.content.pm.ResolveInfo;
@@ skipping 30 matching lines @@
 import org.chromium.chrome.browser.partnerbookmarks.PartnerBookmarksShim;
 import org.chromium.chrome.browser.partnercustomizations.HomepageManager;
 import org.chromium.chrome.browser.partnercustomizations.PartnerBrowserCustomizations;
 import org.chromium.chrome.browser.physicalweb.PhysicalWeb;
 import org.chromium.chrome.browser.precache.PrecacheLauncher;
 import org.chromium.chrome.browser.preferences.ChromePreferenceManager;
 import org.chromium.chrome.browser.preferences.privacy.PrivacyPreferencesManager;
 import org.chromium.chrome.browser.share.ShareHelper;
 import org.chromium.chrome.browser.webapps.ChromeWebApkHost;
 import org.chromium.chrome.browser.webapps.WebApkVersionManager;
-import org.chromium.chrome.browser.webapps.WebappRegistry;
 import org.chromium.content.browser.ChildProcessLauncher;
 
 import java.util.ArrayList;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Locale;
 import java.util.Queue;
 import java.util.concurrent.TimeUnit;
 
 /**
@@ skipping 105 matching lines @@
         ThreadUtils.assertOnUiThread();
 
         RecordHistogram.recordLongTimesHistogram(
                 "UMA.Debug.EnableCrashUpload.DeferredStartUptime2",
                 SystemClock.uptimeMillis() - UmaUtils.getForegroundStartTime(),
                 TimeUnit.MILLISECONDS);
 
         mDeferredTasks.add(new Runnable() {
             @Override
             public void run() {
-                // Initialize the WebappRegistry if it's not already initialized. Must be done on
-                // the main thread.
-                WebappRegistry.getInstance();
-
                 // Punt all tasks that may block on disk off onto a background thread.
                 initAsyncDiskTask();
 
                 AfterStartupTaskUtils.setStartupComplete();
 
                 PartnerBrowserCustomizations.setOnInitializeAsyncFinished(new Runnable() {
                     @Override
                     public void run() {
                         String homepageUrl = HomepageManager.getHomepageUri(mAppContext);
                         LaunchMetrics.recordHomePageLaunchMetrics(
@@ skipping 83 matching lines @@
 
                     removeSnapshotDatabase();
 
                     cacheIsChromeDefaultBrowser();
 
                     RecordHistogram.recordLongTimesHistogram(
                             "UMA.Debug.EnableCrashUpload.DeferredStartUpDurationAsync",
                             SystemClock.uptimeMillis() - asyncTaskStartTime,
                             TimeUnit.MILLISECONDS);
 
-                    // Warm up all web app shared prefs. This must be run after the WebappRegistry
-                    // instance is initialized.
-                    WebappRegistry.warmUpSharedPrefs();
-
                     return null;
                 } finally {
                     TraceEvent.end("ChromeBrowserInitializer.onDeferredStartup.doInBackground");
                 }
             }
-
-            @Override
-            protected void onPostExecute(Void params) {
-                // Must be run on the UI thread after the WebappRegistry has been completely warmed.
-                WebappRegistry.getInstance().unregisterOldWebapps(System.currentTimeMillis());
-            }
         }.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
     }
 
     private void startModerateBindingManagementIfNeeded() {
         // Moderate binding doesn't apply to low end devices.
         if (SysUtils.isLowEndDevice()) return;
 
         boolean moderateBindingTillBackgrounded =
                 FieldTrialList.findFullName("ModerateBindingOnBackgroundTabCreation")
                         .equals("Enabled");
@@ skipping 60 matching lines @@
     }
 
     /**
     * @return Whether deferred startup has been completed.
     */
     @VisibleForTesting
     public boolean isDeferredStartupCompleteForApp() {
         return mDeferredStartupCompletedForApp;
     }
 }