This started happening due to the change to crawl for just in time installable payment apps when no apps are installed. Because many tests include support for "basic-card", the proposed fix is to prevent crawling when merchant request includes "basic-card".

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/e36f41fbab6a8e4d8696e69c3d9c2f600104ca1f

commit e36f41fbab6a8e4d8696e69c3d9c2f600104ca1f
Author: Rouslan Solomakhin <rouslan@chromium.org>
Date: Mon Mar 19 16:27:09 2018

[Payments] Don't crawl installable payment apps with basic-card.

Before this patch, Chrome would crawl for installable payment apps even
when the merchant supported "basic-card" payments. This may slow down
user experience unnecessarily and caused browser tests to issue network
requests.

This patch changes Chrome to crawl for installable payment apps only
when the merchant does not support "basic-card" payments.

After this patch, if merchant supports "basic-card", Chrome does not
crawl for installable payment apps, so the vast majority of browser
tests don't issue network requests anymore.

Bug:  814740 
Change-Id: I79eb156a76ef4f23b953bf399c4f616eee8ac7ad
Reviewed-on: https://chromium-review.googlesource.com/963163
Commit-Queue: Rouslan Solomakhin <rouslan@chromium.org>
Reviewed-by: Ganggui Tang <gogerald@chromium.org>
Cr-Commit-Position: refs/heads/master@{#544058}
[modify] https://crrev.com/e36f41fbab6a8e4d8696e69c3d9c2f600104ca1f/chrome/android/java/src/org/chromium/chrome/browser/payments/AndroidPaymentAppFactory.java
[modify] https://crrev.com/e36f41fbab6a8e4d8696e69c3d9c2f600104ca1f/chrome/android/java/src/org/chromium/chrome/browser/payments/PaymentAppFactory.java
[modify] https://crrev.com/e36f41fbab6a8e4d8696e69c3d9c2f600104ca1f/chrome/android/java/src/org/chromium/chrome/browser/payments/PaymentRequestImpl.java
[modify] https://crrev.com/e36f41fbab6a8e4d8696e69c3d9c2f600104ca1f/chrome/android/java/src/org/chromium/chrome/browser/payments/ServiceWorkerPaymentAppBridge.java
[modify] https://crrev.com/e36f41fbab6a8e4d8696e69c3d9c2f600104ca1f/chrome/android/javatests/src/org/chromium/chrome/browser/payments/PaymentRequestPaymentAppAndBasicCardWithModifiersTest.java
[modify] https://crrev.com/e36f41fbab6a8e4d8696e69c3d9c2f600104ca1f/chrome/android/javatests/src/org/chromium/chrome/browser/payments/PaymentRequestPaymentAppTest.java
[modify] https://crrev.com/e36f41fbab6a8e4d8696e69c3d9c2f600104ca1f/chrome/android/javatests/src/org/chromium/chrome/browser/payments/PaymentRequestPaymentAppsSortingTest.java
[modify] https://crrev.com/e36f41fbab6a8e4d8696e69c3d9c2f600104ca1f/chrome/android/javatests/src/org/chromium/chrome/browser/payments/PaymentRequestServiceWorkerPaymentAppTest.java
[modify] https://crrev.com/e36f41fbab6a8e4d8696e69c3d9c2f600104ca1f/chrome/android/javatests/src/org/chromium/chrome/browser/payments/PaymentRequestTestRule.java
[modify] https://crrev.com/e36f41fbab6a8e4d8696e69c3d9c2f600104ca1f/chrome/browser/android/payments/service_worker_payment_app_bridge.cc
[modify] https://crrev.com/e36f41fbab6a8e4d8696e69c3d9c2f600104ca1f/chrome/browser/payments/service_worker_payment_app_factory_browsertest.cc
[modify] https://crrev.com/e36f41fbab6a8e4d8696e69c3d9c2f600104ca1f/components/payments/content/payment_request_state.cc
[modify] https://crrev.com/e36f41fbab6a8e4d8696e69c3d9c2f600104ca1f/components/payments/content/service_worker_payment_app_factory.cc
[modify] https://crrev.com/e36f41fbab6a8e4d8696e69c3d9c2f600104ca1f/components/payments/content/service_worker_payment_app_factory.h

The following revision refers to this bug:
  https://chrome-internal.googlesource.com/clank/internal/apps/+/c814d2b54ac538a730f7fb97db40bc654ec5f056

commit c814d2b54ac538a730f7fb97db40bc654ec5f056
Author: Rouslan Solomakhin <rouslan@chromium.org>
Date: Mon Mar 19 17:59:02 2018