Clean up lint warnings

chrome/android/java/res/layout/payment_request_spinny.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. -->
 
 <!-- Indeterminate spinny used to show that things are being loaded in the PaymentRequestUi.
      Margins in this file are assigned so that it can be either included or inflated and have
      the correct margins for the situation.  When included in the main bottom sheet, the
      FrameLayout's margins are applied, but they are ignored when this is inflated without
      a parent.
 -->
 <FrameLayout
     xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
+    tools:ignore="MergeRootFrame"
     android:id="@+id/payment_request_spinny"
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
     android:layout_marginBottom="@dimen/payments_section_large_spacing" >
 
     <!-- Indeterminate spinny to show that things are processing. -->
     <ProgressBar
         android:id="@+id/waiting_progress"
         android:layout_width="24dp"
         android:layout_height="24dp"
@@ skipping 11 matching lines @@
         android:layout_gravity="center_horizontal"
         android:layout_marginTop="80dp"
         android:layout_marginStart="@dimen/payments_section_large_spacing"
         android:layout_marginEnd="@dimen/payments_section_large_spacing"
         android:layout_marginBottom="@dimen/payments_section_large_spacing" 
         android:gravity="center_horizontal"
         android:textColor="@color/descriptive_text_color"
         android:textSize="16sp" />
 
 </FrameLayout>