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

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

Index: chrome/android/shell/java/src/org/chromium/chrome/shell/ChromeShellTabModelSelector.java
diff --git a/chrome/android/shell/java/src/org/chromium/chrome/shell/ChromeShellTabModelSelector.java b/chrome/android/shell/java/src/org/chromium/chrome/shell/ChromeShellTabModelSelector.java
index 3d54c086b832a7873bd96e2b499eed04e5c18a9f..096107ec8ccb3a0d652144405cfa5e6ecf58fd0d 100644
--- a/chrome/android/shell/java/src/org/chromium/chrome/shell/ChromeShellTabModelSelector.java
+++ b/chrome/android/shell/java/src/org/chromium/chrome/shell/ChromeShellTabModelSelector.java
@@ -4,9 +4,7 @@
 
 package org.chromium.chrome.shell;
 
-import android.view.LayoutInflater;
 import android.view.ViewGroup;
-import android.view.ViewParent;
 
 import org.chromium.chrome.browser.Tab;
 import org.chromium.chrome.browser.tabmodel.EmptyTabModel;
@@ -68,7 +66,7 @@ class ChromeShellTabModelSelector extends TabModelSelectorBase {
 
             @Override
             public boolean isInOverviewMode() {
-                return isTabSwitcherVisible();
+                return mTabManager.isTabSwitcherVisible();
             }
 
             @Override
@@ -104,44 +102,8 @@ class ChromeShellTabModelSelector extends TabModelSelectorBase {
         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;
+    public AccessibilityTabModelWrapper getTabModelWrapper() {
+        return mTabModelWrapper;
     }
 
 }