Add tab persistence support for CustomTabs.

chrome/android/java/src/org/chromium/chrome/browser/tabmodel/TabModelSelectorImpl.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.tabmodel;
 
 import android.content.Context;
 import android.os.Handler;
 
 import org.chromium.base.VisibleForTesting;
@@ skipping 209 matching lines @@
             @Override
             public void onCrash(Tab tab, boolean sadTabShown) {
                 if (sadTabShown) {
                     mTabContentManager.removeTabThumbnail(tab.getId());
                 }
                 mUma.onTabCrashed(tab.getId());
             }
         };
     }
 
+    /**
+     * Exposed to allow tests to initialize the selector with different tab models.
+     * @param normalModel The normal tab model.
+     * @param incognitoModel The incognito tab model.
+     */
+    @VisibleForTesting
+    public void initializeForTesting(TabModel normalModel, TabModel incognitoModel) {
+        initialize(isIncognitoSelected(), normalModel, incognitoModel);
+        mActiveState = true;
+    }
+
     @Override
     public void setCloseAllTabsDelegate(CloseAllTabsDelegate delegate) {
         mCloseAllTabsDelegate = delegate;
     }
 
     @Override
     public TabModel getModelAt(int index) {
         return mActiveState ? super.getModelAt(index) : EmptyTabModel.getInstance();
     }
 
@@ skipping 175 matching lines @@
     @Override
     public void notifyChanged() {
         super.notifyChanged();
     }
 
     @VisibleForTesting
     public TabPersistentStore getTabPersistentStoreForTesting() {
         return mTabSaver;
     }
 }