Added support to blimp to be usable as a default browser

blimp/client/app/android/java/res/layout/blimp_main.xml

 <?xml version="1.0" encoding="utf-8"?>
 <!-- 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. -->
 
 <merge xmlns:android="http://schemas.android.com/apk/res/android">
     <RelativeLayout
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:orientation="vertical">
@@ skipping 18 matching lines @@
                 android:maxLines="1"
                 android:background="@drawable/textbox"
                 android:textColor="#333" />
             <ImageButton
                 android:id="@+id/toolbar_reload_btn"
                 android:layout_width="48dp"
                 android:layout_height="56dp"
                 android:background="?android:attr/selectableItemBackground"
                 android:scaleType="center"
                 android:src="@drawable/btn_reload" />
+            <ImageButton
+                android:id="@+id/menu_button"
+                android:layout_width="wrap_content"
+                android:layout_height="48dp"
+                android:paddingEnd="4dp"
+                android:layout_gravity="center"
+                android:background="@null"
+                android:src="@drawable/btn_menu" />
         </org.chromium.blimp.toolbar.Toolbar>
         
         <!-- Content Area -->
         <org.chromium.blimp.BlimpView
             android:id="@+id/renderer"
             android:layout_width="match_parent"
             android:layout_height="match_parent"
             android:layout_below="@+id/toolbar"/>
         <org.chromium.blimp.input.WebInputBox
                 android:id="@+id/editText"
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
                 android:background="@drawable/web_input_background"
                 android:layout_alignParentBottom="true"
                 android:layout_marginTop="45dp"
                 android:padding="10dp"
                 android:paddingTop="16dp"
                 android:inputType="text|textWebEditText"
                 android:visibility="gone"/>
 
     </RelativeLayout>
 </merge>