[Payments] If the dialog is gone, bail out

chrome/android/java/src/org/chromium/chrome/browser/payments/PaymentRequestImpl.java

Index: chrome/android/java/src/org/chromium/chrome/browser/payments/PaymentRequestImpl.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/payments/PaymentRequestImpl.java b/chrome/android/java/src/org/chromium/chrome/browser/payments/PaymentRequestImpl.java
index 6106de82b5aa7de9a2dbb37d46d8802ee869faa3..c4914105869511c0bbb4887e8f757e94f0094081 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/payments/PaymentRequestImpl.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/payments/PaymentRequestImpl.java
@@ -999,6 +999,8 @@ public class PaymentRequestImpl implements PaymentRequest, PaymentRequestUI.Clie
      */
     @Override
     public void onInstrumentDetailsReady(String methodName, String stringifiedDetails) {
+        if (mClient == null) return;
+
         PaymentResponse response = new PaymentResponse();
         response.methodName = methodName;
         response.stringifiedDetails = stringifiedDetails;