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

components/payments/content/payment_request.h

 // 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.
 
 #ifndef COMPONENTS_PAYMENTS_CONTENT_PAYMENT_REQUEST_H_
 #define COMPONENTS_PAYMENTS_CONTENT_PAYMENT_REQUEST_H_
 
 #include <memory>
 #include <string>
 #include <vector>
@@ skipping 42 matching lines @@
   // to the renderer which will indirectly destroy this object (through
   // OnConnectionTerminated).
   void UserCancelled();
 
   // As a result of a browser-side error or renderer-initiated mojo channel
   // closure (e.g. there was an error on the renderer side, or payment was
   // successful), this method is called. It is responsible for cleaning up,
   // such as possibly closing the dialog.
   void OnConnectionTerminated();
 
+  // Called when the user clicks on the "Pay" button.
+  void Pay();
+
+  bool is_ready_to_pay() { return is_ready_to_pay_; }
+
   // Returns the CurrencyFormatter instance for this PaymentRequest.
   // |locale_name| should be the result of the browser's GetApplicationLocale().
   // Note: Having multiple currencies per PaymentRequest is not supported; hence
   // the CurrencyFormatter is cached here.
   CurrencyFormatter* GetOrCreateCurrencyFormatter(
       const std::string& currency_code,
       const std::string& currency_system,
       const std::string& locale_name);
 
   // Returns the appropriate Autofill Profiles for this user. On the first
@@ skipping 48 matching lines @@
   void PopulateProfileCache();
 
   // Sets the default values for the selected Shipping and Contact profiles, as
   // well as the selected Credit Card.
   void SetDefaultProfileSelections();
 
   // Validates the |method_data| and fills |supported_card_networks_|.
   void PopulateValidatedMethodData(
       const std::vector<payments::mojom::PaymentMethodDataPtr>& method_data);
 
+  // Updates |is_ready_to_pay_| with the current state, by validating that all
+  // the required information is available.
+  void UpdateIsReadyToPay();
+
+  // Returns whether the selected data satisfies the PaymentDetails requirements
+  // (payment methods).
+  bool ArePaymentDetailsSatisfied();
+  // Returns whether the selected data satisfies the PaymentOptions requirements
+  // (contact info, shipping address).
+  bool ArePaymentOptionsSatisfied();
+
   content::WebContents* web_contents_;
   std::unique_ptr<PaymentRequestDelegate> delegate_;
   // |manager_| owns this PaymentRequest.
   PaymentRequestWebContentsManager* manager_;
   mojo::Binding<payments::mojom::PaymentRequest> binding_;
   payments::mojom::PaymentRequestClientPtr client_;
   payments::mojom::PaymentDetailsPtr details_;
+  payments::mojom::PaymentOptionsPtr options_;
   std::unique_ptr<CurrencyFormatter> currency_formatter_;
   // A set of supported basic card networks.
   std::vector<std::string> supported_card_networks_;
+  bool is_ready_to_pay_;
 
   // Profiles may change due to (e.g.) sync events, so profiles are cached after
   // loading and owned here. They are populated once only, and ordered by
   // frecency.
   std::vector<std::unique_ptr<autofill::AutofillProfile>> profile_cache_;
   std::vector<autofill::AutofillProfile*> shipping_profiles_;
   std::vector<autofill::AutofillProfile*> contact_profiles_;
   autofill::AutofillProfile* selected_shipping_profile_;
   autofill::AutofillProfile* selected_contact_profile_;
   std::vector<std::unique_ptr<autofill::CreditCard>> card_cache_;
   std::vector<autofill::CreditCard*> credit_cards_;
   autofill::CreditCard* selected_credit_card_;
 
   DISALLOW_COPY_AND_ASSIGN(PaymentRequest);
 };
 
 }  // namespace payments
 
 #endif  // COMPONENTS_PAYMENTS_CONTENT_PAYMENT_REQUEST_H_