👀 Cleanup DocumentMode migration helpers.

chrome/android/java/src/org/chromium/chrome/browser/document/DocumentActivity.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.document;
 
 import android.annotation.TargetApi;
 import android.content.Intent;
 import android.graphics.Color;
 import android.os.Build;
@@ skipping 258 matching lines @@
                 if (!SigninPromoUtil.launchSigninPromoIfNeeded(this)) {
                     DataReductionPromoScreen.launchDataReductionPromo(this);
                 }
             } else {
                 preferenceManager.setPromosSkippedOnFirstStart(true);
             }
         }
 
         FirstRunSignInProcessor.start(this);
 
-        if (!preferenceManager.hasAttemptedMigrationOnUpgrade()) {
-            InitializationObserver observer = new InitializationObserver(
-                    ChromeApplication.getDocumentTabModelSelector().getModel(false)) {
-                @Override
-                protected void runImmediately() {
-                    DocumentMigrationHelper.migrateTabsToDocumentForUpgrade(DocumentActivity.this,
-                            DocumentMigrationHelper.FINALIZE_MODE_NO_ACTION);
-                }
-
-                @Override
-                public boolean isSatisfied(int currentState) {
-                    return currentState == DocumentTabModelImpl.STATE_FULLY_LOADED;
-                }
-
-                @Override
-                public boolean isCanceled() {
-                    return false;
-                }
-            };
-
-            observer.runWhenReady();
-        }
-
         getWindow().setFeatureInt(Window.FEATURE_INDETERMINATE_PROGRESS,
                 Window.PROGRESS_VISIBILITY_OFF);
 
         // Initialize the native-side TabModels so that the Profile is available when necessary.
         ChromeApplication.getDocumentTabModelSelector().onNativeLibraryReady();
         mTabInitializationObserver.runWhenReady();
 
         if (mNeedsToBeAddedToTabModel) {
             mNeedsToBeAddedToTabModel = false;
             mTabModel.addTab(getIntent(), mTab);
@@ skipping 565 matching lines @@
 
     /**
      * Launch a new DocumentActivity showing the new tab page.
      * @param incognito Whether the new NTP should be in incognito mode.
      */
     private void launchNtp(boolean incognito) {
         if (incognito && !PrefServiceBridge.getInstance().isIncognitoModeEnabled()) return;
         getTabCreator(incognito).launchNTP();
     }
 }