Adding option for adding new tab in tab manager for chrome shell.

chrome/android/shell/java/src/org/chromium/chrome/shell/ChromeShellTabModelSelector.java

 // Copyright 2014 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.shell;
 
-import android.view.LayoutInflater;
-import android.view.ViewGroup;
-import android.view.ViewParent;
+import android.content.Context;
 
 import org.chromium.chrome.browser.Tab;
 import org.chromium.chrome.browser.tabmodel.EmptyTabModel;
 import org.chromium.chrome.browser.tabmodel.TabModel;
 import org.chromium.chrome.browser.tabmodel.TabModel.TabLaunchType;
 import org.chromium.chrome.browser.tabmodel.TabModel.TabSelectionType;
 import org.chromium.chrome.browser.tabmodel.TabModelDelegate;
 import org.chromium.chrome.browser.tabmodel.TabModelOrderController;
 import org.chromium.chrome.browser.tabmodel.TabModelSelectorBase;
-import org.chromium.chrome.browser.widget.accessibility.AccessibilityTabModelWrapper;
 import org.chromium.content.browser.ContentVideoViewClient;
 import org.chromium.content.browser.ContentViewClient;
 import org.chromium.content_public.browser.LoadUrlParams;
 import org.chromium.ui.base.WindowAndroid;
 
 /**
  * Basic implementation of TabModelSelector for use in ChromeShell. Only has a regular TabModel,
  * no incognito one.
  */
 class ChromeShellTabModelSelector extends TabModelSelectorBase {
 
     private final WindowAndroid mWindow;
     private final ContentVideoViewClient mContentVideoViewClient;
-    private final ViewGroup mParent;
+    private final Context mContext;
     private final TabModelOrderController mOrderController;
 
-    private AccessibilityTabModelWrapper mTabModelWrapper;
     private TabManager mTabManager;
 
     public ChromeShellTabModelSelector(
-            WindowAndroid window, ContentVideoViewClient videoViewClient, ViewGroup parent,
+            WindowAndroid window, ContentVideoViewClient videoViewClient, Context context,
             TabManager tabManager) {
         mWindow = window;
         mContentVideoViewClient = videoViewClient;
-        mParent = parent;
+        mContext = context;
         mOrderController = new TabModelOrderController(this);
         mTabManager = tabManager;
 
         TabModelDelegate tabModelDelegate = new TabModelDelegate() {
             @Override
             public void didCreateNewTab(Tab tab) {}
 
             @Override
             public void didChange() {}
 
             @Override
             public void selectModel(boolean incognito) {
                 assert !incognito;
             }
 
             @Override
             public void requestToShowTab(Tab tab, TabSelectionType type) {
             }
 
             @Override
             public boolean isSessionRestoreInProgress() {
                 return false;
             }
 
             @Override
             public boolean isInOverviewMode() {
-                return isTabSwitcherVisible();
+                return mTabManager.isTabSwitcherVisible();
             }
 
             @Override
             public TabModel getModel(boolean incognito) {
                 return ChromeShellTabModelSelector.this.getModel(incognito);
             }
 
             @Override
             public TabModel getCurrentModel() {
                 return ChromeShellTabModelSelector.this.getCurrentModel();
             }
         };
         TabModel tabModel = new ChromeShellTabModel(mOrderController, tabModelDelegate);
         initialize(false, tabModel, EmptyTabModel.getInstance());
     }
 
     @Override
     public Tab openNewTab(LoadUrlParams loadUrlParams, TabLaunchType type, Tab parent,
             boolean incognito) {
         assert !incognito;
         ContentViewClient client = new ContentViewClient() {
             @Override
             public ContentVideoViewClient getContentVideoViewClient() {
                 return mContentVideoViewClient;
             }
         };
         ChromeShellTab tab = new ChromeShellTab(
-                mParent.getContext(), loadUrlParams.getUrl(), mWindow, client, mTabManager);
+                mContext, loadUrlParams.getUrl(), mWindow, client, mTabManager);
         int index = mOrderController.determineInsertionIndex(type, tab);
         TabModel tabModel = getCurrentModel();
         tabModel.addTab(tab, index, type);
         tabModel.setIndex(index, TabSelectionType.FROM_NEW);
         return tab;
     }
 
-    /**
-     * Toggles the tab switcher visibility.
-     */
-    public void toggleTabSwitcher() {
-        if (!isTabSwitcherVisible()) {
-            showTabSwitcher();
-        } else {
-            hideTabSwitcher();
-        }
-    }
-
-    /*
-     * Hide the tab switcher.
-     */
-    public void hideTabSwitcher() {
-        if (mTabModelWrapper == null) return;
-        ViewParent parent = mTabModelWrapper.getParent();
-        if (parent != null) {
-            assert parent == mParent;
-            mParent.removeView(mTabModelWrapper);
-        }
-    }
-
-    private void showTabSwitcher() {
-        if (mTabModelWrapper == null) {
-            mTabModelWrapper = (AccessibilityTabModelWrapper) LayoutInflater.from(
-                    mParent.getContext()).inflate(R.layout.accessibility_tab_switcher, null);
-            mTabModelWrapper.setup(null);
-            mTabModelWrapper.setTabModelSelector(this);
-        }
-
-        if (mTabModelWrapper.getParent() == null) {
-            mParent.addView(mTabModelWrapper);
-        }
-    }
-
-    public boolean isTabSwitcherVisible() {
-        return mTabModelWrapper != null && mTabModelWrapper.getParent() == mParent;
-    }
-
 }