Warn web developer on missing favicon for PaymentRequest UI.

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 61164ab434b43ec87f4695ee7747a9ce85f940bc..ec678a223910238f8531726ff9b4599e442bb2ba 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
@@ -527,6 +527,7 @@ public class PaymentRequestImpl implements PaymentRequest, PaymentRequestUI.Clie
                 new FaviconHelper.FaviconImageCallback() {
                     @Override
                     public void onFaviconAvailable(Bitmap bitmap, String iconUrl) {
+                        if (mClient != null && bitmap == null) mClient.warnNoFavicon();
                         if (mUI != null && bitmap != null) mUI.setTitleBitmap(bitmap);
                         faviconHelper.destroy();
                     }