[Payments] Add the pay button, and control its enabled state

chrome/browser/payments/chrome_payment_request_delegate.cc

 // Copyright 2017 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.
 
 #include "chrome/browser/payments/chrome_payment_request_delegate.h"
 
 #include "base/macros.h"
 #include "chrome/browser/autofill/personal_data_manager_factory.h"
+#include "chrome/browser/browser_process.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser_dialogs.h"
 #include "components/payments/content/payment_request_dialog.h"
 #include "content/public/browser/web_contents.h"
 
 namespace payments {
 
 ChromePaymentRequestDelegate::ChromePaymentRequestDelegate(
     content::WebContents* web_contents)
     : dialog_(nullptr), web_contents_(web_contents) {}
@@ skipping 10 matching lines @@
     dialog_ = nullptr;
   }
 }
 
 autofill::PersonalDataManager*
 ChromePaymentRequestDelegate::GetPersonalDataManager() {
   return autofill::PersonalDataManagerFactory::GetForProfile(
       Profile::FromBrowserContext(web_contents_->GetBrowserContext()));
 }
 
+const std::string& ChromePaymentRequestDelegate::GetApplicationLocale() const {
+  return g_browser_process->GetApplicationLocale();
+}
+
 }  // namespace payments