[Payments] Implement web payment app manifest

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

Index: third_party/WebKit/Source/modules/payments/PaymentInstruments.cpp
diff --git a/third_party/WebKit/Source/modules/payments/PaymentInstruments.cpp b/third_party/WebKit/Source/modules/payments/PaymentInstruments.cpp
index 2da969b6564dcf4671b54b3554536e00ca35e578..b680bf9d12722e75057c13bb5d59a849ea59fb4e 100644
--- a/third_party/WebKit/Source/modules/payments/PaymentInstruments.cpp
+++ b/third_party/WebKit/Source/modules/payments/PaymentInstruments.cpp
@@ -11,6 +11,7 @@
 #include "bindings/core/v8/ScriptPromiseResolver.h"
 #include "bindings/core/v8/V8BindingForCore.h"
 #include "core/dom/DOMException.h"
+#include "core/inspector/ConsoleMessage.h"
 #include "modules/payments/PaymentInstrument.h"
 #include "modules/payments/PaymentManager.h"
 #include "platform/wtf/Vector.h"
@@ -46,6 +47,19 @@ bool rejectError(ScriptPromiseResolver* resolver,
       resolver->Reject(DOMException::Create(
           kNotFoundError, "Fetch or decode instrument icon failed"));
       return true;
+    case payments::mojom::blink::PaymentHandlerStatus::
+        FETCH_PAYMENT_APP_INFO_FAILED:
+      // FETCH_PAYMENT_APP_INFO_FAILED indicates everything works well except
+      // fetching payment app's manifest. The alternative value for the payment
+      // app will be used in this case, so only show warnning message instead of
+      // reject the promise.
+      ExecutionContext* context =
+          ExecutionContext::From(resolver->GetScriptState());
+      context->AddConsoleMessage(
+          ConsoleMessage::Create(kJSMessageSource, kWarningMessageLevel,
+                                 "Fetch payment app's info (manifest or the "
+                                 "field in the manifest) failed."));

[please use gerrit instead, 2017/06/30 15:43:30]

A couple of comments:

1) Payment app is not the terminology used by W3C. They call it "payment
handler". Let's use that language as well.

2) Let the web developer know what is the impact of this error.

Here's the text that I propose:

"Unable to fetch payment handler's name and icon from its web app manifest. User
may not recognize this payment handler in UI, because it will be labeled only by
its origin."

[gogerald1, 2017/06/30 16:25:09]

Done.

+      return false;
   }
   NOTREACHED();
   return false;