Remove PaymentResponse.totalAmount according to latest spec

chrome/android/java/src/org/chromium/chrome/browser/payments/PaymentRequestImpl.java

 // 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.
 
 package org.chromium.chrome.browser.payments;
 
 import android.app.Activity;
 import android.graphics.Bitmap;
 import android.os.Handler;
 import android.text.TextUtils;
@@ skipping 684 matching lines @@
         }
     }
 
     /**
      * Called after retrieving instrument details.
      */
     @Override
     public void onInstrumentDetailsReady(String methodName, String stringifiedDetails) {
         PaymentResponse response = new PaymentResponse();
         response.methodName = methodName;
-        response.totalAmount = mRawTotal.amount;
         response.stringifiedDetails = stringifiedDetails;
 
         if (mContactSection != null) {
             PaymentOption selectedContact = mContactSection.getSelectedItem();
             if (selectedContact != null) {
                 // Contacts are created in show(). These should all be instances of AutofillContact.
                 assert selectedContact instanceof AutofillContact;
                 response.payerEmail = ((AutofillContact) selectedContact).getPayerEmail();
                 response.payerPhone = ((AutofillContact) selectedContact).getPayerPhone();
             }
@@ skipping 63 matching lines @@
     private void closeClient() {
         if (mClient != null) mClient.close();
         mClient = null;
     }
 
     @VisibleForTesting
     public static void setObserverForTest(PaymentRequestServiceObserverForTest observerForTest) {
         sObserverForTest = observerForTest;
     }
 }