Add menu button to menu

chrome/android/shell/res/layout/chrome_shell_activity.xml

 <?xml version="1.0" encoding="utf-8"?>
 
 <!-- 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.
  -->
 
 <org.chromium.chrome.shell.TabManager android:id="@+id/tab_manager"
     xmlns:android="http://schemas.android.com/apk/res/android"
@@ skipping 14 matching lines @@
             android:autoText="true"
             android:capitalize="sentences"
             android:singleLine="true"
             android:selectAllOnFocus="true"
             android:hint="@string/url_hint"
             android:inputType="textUri"
             android:imeOptions="actionGo|flagNoExtractUi" />
         <ImageButton android:id="@+id/menu_button"
             android:layout_width="38dp"
             android:layout_height="38dp"
-            android:src="@drawable/menu_dots"
+            android:src="@drawable/btn_menu"
             android:background="?android:attr/selectableItemBackground"
             android:scaleType="center" />
     </org.chromium.chrome.shell.ChromeShellToolbar>
     <FrameLayout android:id="@+id/content_container"
         android:layout_width="match_parent"
         android:layout_height="0dp"
         android:layout_weight="1">
     </FrameLayout>
 
 </org.chromium.chrome.shell.TabManager>