Java implementation of PaymentRequest mojo service

chrome/android/java/src/org/chromium/chrome/browser/payments/ui/PaymentRequestUI.java

Index: chrome/android/java/src/org/chromium/chrome/browser/payments/ui/PaymentRequestUI.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/payments/ui/PaymentRequestUI.java b/chrome/android/java/src/org/chromium/chrome/browser/payments/ui/PaymentRequestUI.java
index 6d939b74e610e67d4a019611cac1148fc463ec7f..e63247b6288de80568e133fd037f234d91a6a5e8 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/payments/ui/PaymentRequestUI.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/payments/ui/PaymentRequestUI.java
@@ -227,6 +227,8 @@ public class PaymentRequestUI implements DialogInterface.OnDismissListener, View
                 ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);
         mDialog.show();
 
+        updatePayButtonEnabled();
+
         mClient.getDefaultPaymentInformation(new Callback<PaymentInformation>() {
             public void onResult(PaymentInformation result) {
                 updateLineItems(result.getLineItems());
@@ -250,6 +252,8 @@ public class PaymentRequestUI implements DialogInterface.OnDismissListener, View
 
                 mPaymentMethodsSection = result.getPaymentMethods();
                 updateSection(mPaymentMethods, mPaymentMethodsSection, null);
+
+                updatePayButtonEnabled();
             }
         });
     }
@@ -482,8 +486,7 @@ public class PaymentRequestUI implements DialogInterface.OnDismissListener, View
                             ? null : mShippingAddressesSection.getSelectedItem(),
                     mShippingOptionsSection == null
                             ? null : mShippingOptionsSection.getSelectedItem(),
-                    mPaymentMethodsSection == null
-                            ? null : mPaymentMethodsSection.getSelectedItem());
+                    mPaymentMethodsSection.getSelectedItem());
         } else if (v == mEditButton) {
             if (mSelectedSection == null) {
                 expand(mOrderSummaryLabel, mOrderSummary);
@@ -502,6 +505,22 @@ public class PaymentRequestUI implements DialogInterface.OnDismissListener, View
                 mClient.onPaymentMethodChanged(tag.getSection().getSelectedItem());
             }
         }
+
+        updatePayButtonEnabled();
+    }
+
+    private void updatePayButtonEnabled() {
+        if (mRequestShipping) {
+            mPayButton.setEnabled(mShippingAddressesSection != null
+                    && mShippingAddressesSection.getSelectedItem() != null
+                    && mShippingOptionsSection != null
+                    && mShippingOptionsSection.getSelectedItem() != null
+                    && mPaymentMethodsSection != null
+                    && mPaymentMethodsSection.getSelectedItem() != null);
+        } else {
+            mPayButton.setEnabled(mPaymentMethodsSection != null
+                    && mPaymentMethodsSection.getSelectedItem() != null);
+        }
     }
 
     private void expand(View sectionLabel, ViewGroup section) {