PaymentHandler: Implement GetAllPaymentApps().

content/browser/payments/payment_app.proto

Index: content/browser/payments/payment_app.proto
diff --git a/content/browser/payments/payment_app.proto b/content/browser/payments/payment_app.proto
index 43a444ac55d159af9d173f6e5cc324ad470be2d7..88a2b2787f3e07664446659ab875dd9eff101951 100644
--- a/content/browser/payments/payment_app.proto
+++ b/content/browser/payments/payment_app.proto
@@ -21,13 +21,16 @@ message PaymentAppOptionProto {
   repeated string enabled_methods = 4;
 }
 
-message PaymentInstrumentKeyInfoProto {
+message StoredPaymentInstrumentKeyInfoProto {
   optional uint64 insertion_order = 1;
   optional string key = 2;
 }
 
-message PaymentInstrumentProto {
-  optional string name = 1;
-  repeated string enabled_methods = 2;
-  optional string stringified_capabilities = 3;
+message StoredPaymentInstrumentProto {
+  optional int64 registration_id = 1;
+  optional string instrument_key = 2;
+  optional string origin = 3;
+  optional string name = 4;
+  repeated string enabled_methods = 5;
+  optional string stringified_capabilities = 6;
 }