Remove superfluous closeUI call

Remove superfluous closeUI call from onDismiss, this is
already done in disconnectFromClientWithDebugMessage.

BUG=587995

Review-Url: https://codereview.chromium.org/2536783002
Cr-Commit-Position: refs/heads/master@{#434708}

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

@@ -944,7 +944,6 @@ public class PaymentRequestImpl implements PaymentRequest, PaymentRequestUI.Clie
     @Override
     public void onDismiss() {
         disconnectFromClientWithDebugMessage("Dialog dismissed");
-        closeUI(true);
         recordAbortReasonHistogram(PaymentRequestMetrics.ABORT_REASON_ABORTED_BY_USER);
     }