[Web Payments] Implement the CVC Unmask dialog.

components/payments/content/payment_request_state.h

Index: components/payments/content/payment_request_state.h
diff --git a/components/payments/content/payment_request_state.h b/components/payments/content/payment_request_state.h
index 19f9979b59f17dd1acc49c2012e9e0831efb7761..e2b39b3431268ed75dc3806348e17903b07da51b 100644
--- a/components/payments/content/payment_request_state.h
+++ b/components/payments/content/payment_request_state.h
@@ -21,6 +21,7 @@ class PersonalDataManager;
 namespace payments {
 
 class PaymentRequestSpec;
+class PaymentRequestDelegate;
 
 // Keeps track of the information currently selected by the user and whether the
 // user is ready to pay. Uses information from the PaymentRequestSpec, which is
@@ -45,6 +46,7 @@ class PaymentRequestState : public PaymentInstrument::Delegate {
     // Called when the PaymentResponse is available.
     virtual void OnPaymentResponseAvailable(
         mojom::PaymentResponsePtr response) = 0;
+    virtual PaymentRequestDelegate* GetPaymentRequestDelegate() = 0;
 
     // Called when the shipping option has changed to |shipping_option_id|.
     virtual void OnShippingOptionIdSelected(std::string shipping_option_id) = 0;
@@ -120,6 +122,8 @@ class PaymentRequestState : public PaymentInstrument::Delegate {
   const std::string& GetApplicationLocale();
   autofill::PersonalDataManager* GetPersonalDataManager();
 
+  Delegate* delegate() { return delegate_; }
+
  private:
   // Fetches the Autofill Profiles for this user from the PersonalDataManager,
   // and stores copies of them, owned by this PaymentRequestState, in