Warn web developers that card networks as method names are deprecated.

third_party/WebKit/Source/modules/payments/PaymentRequest.cpp

Index: third_party/WebKit/Source/modules/payments/PaymentRequest.cpp
diff --git a/third_party/WebKit/Source/modules/payments/PaymentRequest.cpp b/third_party/WebKit/Source/modules/payments/PaymentRequest.cpp
index 9759e63f2eccaaa13af83dcfd05b94e0cb542119..3425dc0b68113f90686c235aa9189f536ce25a63 100644
--- a/third_party/WebKit/Source/modules/payments/PaymentRequest.cpp
+++ b/third_party/WebKit/Source/modules/payments/PaymentRequest.cpp
@@ -128,6 +128,20 @@ struct TypeConverter<PaymentOptionsPtr, blink::PaymentOptions> {
 namespace blink {
 namespace {
 
+using ::payments::mojom::blink::BasicCardNetwork;
+
+const struct {
+  const BasicCardNetwork code;
+  const char* const name;
+} kBasicCardNetworks[] = {{BasicCardNetwork::AMEX, "amex"},
+                          {BasicCardNetwork::DINERS, "diners"},
+                          {BasicCardNetwork::DISCOVER, "discover"},
+                          {BasicCardNetwork::JCB, "jcb"},
+                          {BasicCardNetwork::MASTERCARD, "mastercard"},
+                          {BasicCardNetwork::MIR, "mir"},
+                          {BasicCardNetwork::UNIONPAY, "unionpay"},
+                          {BasicCardNetwork::VISA, "visa"}};
+
 // If the website does not call complete() 60 seconds after show() has been
 // resolved, then behave as if the website called complete("fail").
 static const int kCompleteTimeoutSeconds = 60;
@@ -349,20 +363,6 @@ void SetBasicCardMethodData(const ScriptValue& input,
     return;
 
   if (basic_card.hasSupportedNetworks()) {
-    using ::payments::mojom::blink::BasicCardNetwork;
-
-    const struct {
-      const BasicCardNetwork code;
-      const char* const name;
-    } kBasicCardNetworks[] = {{BasicCardNetwork::AMEX, "amex"},
-                              {BasicCardNetwork::DINERS, "diners"},
-                              {BasicCardNetwork::DISCOVER, "discover"},
-                              {BasicCardNetwork::JCB, "jcb"},
-                              {BasicCardNetwork::MASTERCARD, "mastercard"},
-                              {BasicCardNetwork::MIR, "mir"},
-                              {BasicCardNetwork::UNIONPAY, "unionpay"},
-                              {BasicCardNetwork::VISA, "visa"}};
-
     for (const String& network : basic_card.supportedNetworks()) {
       for (size_t i = 0; i < arraysize(kBasicCardNetworks); ++i) {
         if (network == kBasicCardNetworks[i].name) {
@@ -400,6 +400,22 @@ void SetBasicCardMethodData(const ScriptValue& input,
   }
 }
 
+void WarnDeprecatedBasicCard(const Vector<String>& supported_methods,
+                             ExecutionContext& execution_context) {
+  for (const auto& method : supported_methods) {
+    for (size_t i = 0; i < arraysize(kBasicCardNetworks); ++i) {
+      if (method == kBasicCardNetworks[i].name) {
+        execution_context.AddConsoleMessage(ConsoleMessage::Create(
+            kJSMessageSource, kWarningMessageLevel,

[Rick Byers, 2017/05/16 13:48:58]

Please use the "DeprecationMessageSource" - that'll get picked up eg. by
lighthouse.  Can you use the common deprecation infrastructure in
Deprecation.cpp instead of rolling it yourself?

[please use gerrit instead, 2017/05/16 18:02:55]

Done.

+            "The supported methods 'amex', 'diners', 'discover', 'jcb', "
+            "'mastercard', 'mir', 'unionpay', and 'visa' are deprecated. Use "
+            "'basic-card' instead."));

[Rick Byers, 2017/05/16 13:48:58]

In general we prefer to give developers a concrete planned removal milestone and
chromestatus.com link for more context.

[please use gerrit instead, 2017/05/16 18:02:55]

Done.

+        return;
+      }
+    }
+  }
+}
+
 void StringifyAndParseMethodSpecificData(
     const Vector<String>& supported_methods,
     const ScriptValue& input,
@@ -434,6 +450,7 @@ void StringifyAndParseMethodSpecificData(
     if (exception_state.HadException())
       exception_state.ClearException();
   }
+  WarnDeprecatedBasicCard(supported_methods, execution_context);
 }
 
 void ValidateAndConvertPaymentDetailsModifiers(