Added a UI for the Interests Prototype.

chrome/android/java/res/layout/new_tab_page.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. -->
 
 <org.chromium.chrome.browser.ntp.NewTabPageView
     xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:chrome="http://schemas.android.com/apk/res-auto"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
@@ skipping 172 matching lines @@
                 android:layout_width="wrap_content"
                 android:layout_height="match_parent"
                 android:layout_gravity="center_horizontal"
                 android:drawablePadding="8dp"
                 android:gravity="center_vertical"
                 android:text="@string/ntp_bookmarks"
                 android:textSize="12sp"
                 android:textColor="#5a5a5a" />
         </FrameLayout>
         <FrameLayout
+            android:background="?attr/listChoiceBackgroundIndicator"
+            android:contentDescription="@string/accessibility_ntp_toolbar_btn_interests"
+            android:id="@+id/interests_button"
+            android:layout_height="match_parent"
+            android:layout_weight="1"
+            android:layout_width="0dp"
+            android:paddingBottom="12dp"
+            android:paddingTop="12dp"
+            android:visibility="gone" >
+            <TextView
+                android:drawablePadding="8dp"
+                android:gravity="center_vertical"
+                android:layout_gravity="center_horizontal"
+                android:layout_height="match_parent"
+                android:layout_width="wrap_content"
+                android:text="@string/ntp_interests"
+                android:textColor="#5a5a5a"
+                android:textSize="12sp" />
+        </FrameLayout>
+        <FrameLayout
             android:id="@+id/recent_tabs_button"
             android:layout_width="0dp"
             android:layout_height="match_parent"
             android:layout_weight="1"
             android:background="?attr/listChoiceBackgroundIndicator"
             android:contentDescription="@string/accessibility_ntp_toolbar_btn_recent_tabs"
             android:paddingTop="12dp"
             android:paddingBottom="12dp" >
             <TextView
                 android:layout_width="wrap_content"
                 android:layout_height="match_parent"
                 android:layout_gravity="center_horizontal"
                 android:drawablePadding="8dp"
                 android:gravity="center_vertical"
                 android:text="@string/recent_tabs"
                 android:textSize="12sp"
                 android:textColor="#5a5a5a" />
         </FrameLayout>
     </org.chromium.chrome.browser.ntp.NewTabPageToolbar>
 </org.chromium.chrome.browser.ntp.NewTabPageView>