[Payment Handler] CanMakePaymentEvent.respondWithMinimalUI() #1

Patch #1: Add Blink API for CanMakePaymentEvent.respondWithMinimalUI()
and CanMakePaymentEvent.currency according to the explainer for Minimal
UI payment handlers:
https://gist.github.com/rsolomakhin/eba91c185028899883d2c7f37f357d7c

The additional API surface is disabled by default and can be enabled via
chrome://flags/#enable-experimental-web-platform-features.

Demo: https://rsolomakhin.github.io/pr/apps/micro/

Chrome feature status:
https://chromestatus.com/feature/5661524146257920.

Blink-dev intent to prototype:
https://groups.google.com/a/chromium.org/d/msg/blink-dev/kTLpgFJz6Ck/IQeiGDtOAwAJ

Bug: 1005076
Change-Id: Id3d472a07992007e17c7dec4f4d826eaa84c309b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2071108Reviewed-by: Danyao Wang <danyao@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Rouslan Solomakhin <rouslan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#744725}

third_party/blink/renderer/bindings/idl_in_modules.gni

@@ -400,6 +400,7 @@ static_idl_files_in_modules = get_path_info(
           "//third_party/blink/renderer/modules/payments/basic_card_request.idl",
           "//third_party/blink/renderer/modules/payments/can_make_payment_event.idl",
           "//third_party/blink/renderer/modules/payments/can_make_payment_event_init.idl",
+          "//third_party/blink/renderer/modules/payments/can_make_payment_response.idl",
           "//third_party/blink/renderer/modules/payments/html_iframe_element_payments.idl",
           "//third_party/blink/renderer/modules/payments/image_object.idl",
           "//third_party/blink/renderer/modules/payments/merchant_validation_event.idl",

third_party/blink/renderer/modules/payments/can_make_payment_event.cc

@@ -70,6 +70,17 @@ void CanMakePaymentEvent::respondWith(ScriptState* script_state,
   }
 }
 
+const String& CanMakePaymentEvent::currency() const {
+  return currency_;
+}
+
+void CanMakePaymentEvent::respondWithMinimalUI(
+    ScriptState* script_state,
+    ScriptPromise script_promise,
+    ExceptionState& exception_state) {
+  respondWith(script_state, script_promise, exception_state);
+}
+
 void CanMakePaymentEvent::Trace(Visitor* visitor) {
   visitor->Trace(method_data_);
   visitor->Trace(modifiers_);
@@ -91,6 +102,7 @@ CanMakePaymentEvent::CanMakePaymentEvent(
       modifiers_(initializer->hasModifiers()
                      ? initializer->modifiers()
                      : HeapVector<Member<PaymentDetailsModifier>>()),
+      currency_(initializer->currency()),
       observer_(respond_with_observer) {}
 
 }  // namespace blink

third_party/blink/renderer/modules/payments/can_make_payment_event.h

@@ -49,6 +49,9 @@ class MODULES_EXPORT CanMakePaymentEvent final : public ExtendableEvent {
 
   void respondWith(ScriptState*, ScriptPromise, ExceptionState&);
 
+  const String& currency() const;
+  void respondWithMinimalUI(ScriptState*, ScriptPromise, ExceptionState&);
+
   void Trace(Visitor*) override;
 
  private:
@@ -56,6 +59,7 @@ class MODULES_EXPORT CanMakePaymentEvent final : public ExtendableEvent {
   String payment_request_origin_;
   HeapVector<Member<PaymentMethodData>> method_data_;
   HeapVector<Member<PaymentDetailsModifier>> modifiers_;
+  String currency_;
 
   Member<RespondWithObserver> observer_;
 

third_party/blink/renderer/modules/payments/can_make_payment_event.idl

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// https://github.com/w3c/payment-handler/pull/170
+// https://w3c.github.io/payment-handler/#the-canmakepaymentevent
 
 [
     RuntimeEnabled=PaymentApp,
@@ -15,4 +15,8 @@
     readonly attribute FrozenArray<PaymentDetailsModifier> modifiers;
 
     [CallWith=ScriptState, RaisesException] void respondWith(Promise<boolean> canMakePaymentResponse);
+
+    // https://gist.github.com/rsolomakhin/eba91c185028899883d2c7f37f357d7c
+    [RuntimeEnabled=PaymentHandlerMinimalUI] readonly attribute DOMString currency;
+    [RuntimeEnabled=PaymentHandlerMinimalUI, CallWith=ScriptState, RaisesException] void respondWithMinimalUI(Promise<CanMakePaymentResponse> response);
 };

third_party/blink/renderer/modules/payments/can_make_payment_event_init.idl

@@ -9,4 +9,7 @@ dictionary CanMakePaymentEventInit : ExtendableEventInit {
     USVString paymentRequestOrigin;
     sequence<PaymentMethodData> methodData;
     sequence<PaymentDetailsModifier> modifiers;
+
+    // https://gist.github.com/rsolomakhin/eba91c185028899883d2c7f37f357d7c
+    DOMString currency;
 };

third_party/blink/renderer/modules/payments/can_make_payment_response.idl

+// Copyright 2020 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.
+
+// https://gist.github.com/rsolomakhin/eba91c185028899883d2c7f37f357d7c
+
+dictionary CanMakePaymentResponse {
+    boolean canMakePayment;
+    boolean readyForMinimalUI;
+    DOMString accountBalance;
+};

third_party/blink/renderer/modules/payments/idls.gni

@@ -21,6 +21,7 @@ modules_dictionary_idl_files = [
   "android_pay_method_data.idl",
   "basic_card_request.idl",
   "can_make_payment_event_init.idl",
+  "can_make_payment_response.idl",
   "image_object.idl",
   "merchant_validation_event_init.idl",
   "payer_errors.idl",

third_party/blink/renderer/platform/runtime_enabled_features.json5

@@ -1283,6 +1283,10 @@
       name: "PaymentHandlerHandlesShippingAndContact",
       status: "stable",
     },
+    {
+      name: "PaymentHandlerMinimalUI",
+      status: "experimental",
+    },
     {
       name: "PaymentMethodChangeEvent",
       status: "stable",

third_party/blink/web_tests/http/tests/serviceworker/webexposed/global-interface-listing-service-worker-expected.txt

@@ -108,12 +108,14 @@ interface CacheStorage
     method open
 interface CanMakePaymentEvent : ExtendableEvent
     attribute @@toStringTag
+    getter currency
     getter methodData
     getter modifiers
     getter paymentRequestOrigin
     getter topOrigin
     method constructor
     method respondWith
+    method respondWithMinimalUI
 interface CanvasGradient
     attribute @@toStringTag
     method addColorStop