Chrome Version       : Canary
OS Version: Android 7.1.2 Nougat
URLs (if applicable) : https://rsolomakhin.github.io/pr/

What steps will reproduce the problem?
1. Enable chrome://flags/#enable-experimental-web-platform-features
2. Open https://rsolomakhin.github.io/pr/.
3. Click "Buy".
4. If not already selected, select a non-mastercard payment method.

What is the expected result?
Mastercard discount should not be applied.

What happens instead of that?
Mastercard discount is applied.

JS code:
  const supportedInstruments = [{
    supportedMethods: ['https://android.com/pay'],
    data: {
      merchantName: 'Rouslan Solomakhin',
      merchantId: '00184145120947117657',
      allowedCardNetworks: ['AMEX', 'MASTERCARD', 'VISA', 'DISCOVER'],
      paymentMethodTokenizationParameters: {
        tokenizationType: 'GATEWAY_TOKEN',
        parameters: {
          'gateway': 'stripe',
          'stripe:publishableKey': 'pk_live_lNk21zqKM2BENZENh3rzCUgo',
          'stripe:version': '2016-07-06',
        },
      },
    },
  }, {
    supportedMethods: ['basic-card'],
  }];

  const details = {
    total: {
      label: 'Donation',
      amount: {
        currency: 'USD',
        value: '55.00',
      },
    },
    displayItems: [{
      label: 'Original donation amount',
      amount: {
        currency: 'USD',
        value: '65.00',
      },
    }, {
      label: 'Friends and family discount',
      amount: {
        currency: 'USD',
        value: '-10.00',
      },
    }],
    modifiers: [{
      supportedMethods: ['basic-card'],
      data: {
        supportedTypes: ['debit'],
      },
      total: {
        label: 'Debit card discounted donation',
        amount: {
          currency: 'USD',
          value: '45.00',
        },
      },
      additionalDisplayItems: [{
        label: 'Debit card discount',
        amount: {
          currency: 'USD',
          value: '-10.00',
        },
      }],
    }, {
      supportedMethods: ['basic-card'],
      data: {
        supportedNetworks: ['mastercard'],
      },
      total: {
        label: 'MasterCard discounted donation',
        amount: {
          currency: 'USD',
          value: '50.00',
        },
      },
      additionalDisplayItems: [{
        label: 'MasterCard discount',
        amount: {
          currency: 'USD',
          value: '-5.00',
        },
      }],
    }],
  };

  try {
    PaymentRequest(supportedInstruments, details).show();
  } catch (e) {
    error('Developer mistake: \'' + e + '\'');
  }