Update and unify nine-patch files for content suggestion and omnibox cards

chrome/android/java/res/layout/new_tab_page_layout.xml

 <?xml version="1.0" encoding="utf-8"?>
 <!-- Copyright 2016 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.NewTabPageLayout
     xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:chrome="http://schemas.android.com/apk/res-auto"
     android:id="@+id/ntp_content"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
@@ skipping 46 matching lines @@
     <!-- Search box -->
     <LinearLayout
         android:id="@+id/search_box"
         android:layout_width="match_parent"
         android:layout_height="@dimen/ntp_search_box_height"
         android:layout_marginStart="10dp"
         android:layout_marginEnd="10dp"
         android:layout_marginTop="0dp"
         android:layout_marginBottom="1dp"
         android:gravity="center_vertical"
-        android:background="@drawable/textbox"
+        android:background="@drawable/card_single"
         android:orientation="horizontal"
         android:paddingStart="2dp"
         android:paddingEnd="2dp"
         android:paddingTop="3dp"
         android:paddingBottom="3dp" >
         <EditText
             android:id="@+id/search_box_text"
             android:layout_width="0dp"
             android:layout_height="match_parent"
             android:layout_marginStart="12dp"
@@ skipping 61 matching lines @@
         android:layout_weight="1"
         android:visibility="gone" />
 
     <!-- Spacer to make the page scrollable when needed. -->
     <View
         android:id="@+id/ntp_scroll_spacer"
         android:layout_width="match_parent"
         android:layout_height="0dp"
         android:visibility="gone" />
 </org.chromium.chrome.browser.ntp.NewTabPageLayout>