[Payments] Move PaymentResponse logic to PaymentResponseHelper.

components/payments/content/BUILD.gn

 # 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.
 
 import("//mojo/public/tools/bindings/mojom.gni")
 
 static_library("content") {
   sources = [
     "payment_request.cc",
     "payment_request.h",
@@ skipping 79 matching lines @@
     "//third_party/libaddressinput",
   ]
 }
 
 source_set("unit_tests") {
   testonly = true
   sources = [
     "payment_manifest_downloader_unittest.cc",
     "payment_request_spec_unittest.cc",
     "payment_request_state_unittest.cc",
+    "payment_response_helper_unittest.cc",
     "payments_validators_unittest.cc",
   ]
 
   deps = [
     ":content",
     ":mojom",
     ":utils",
     "//base",
     "//base/test:test_support",
     "//components/autofill/core/browser",
     "//components/autofill/core/browser:test_support",
     "//components/payments/core",
     "//content/test:test_support",
     "//net:test_support",
     "//testing/gtest",
     "//third_party/icu",
     "//third_party/libaddressinput:test_support",
   ]
 }