Add the Mojo implementation of authenticator.mojom's MakeCredential.

third_party/WebKit/public/BUILD.gn

Index: third_party/WebKit/public/BUILD.gn
diff --git a/third_party/WebKit/public/BUILD.gn b/third_party/WebKit/public/BUILD.gn
index 1cfc957b372ae432ef464f6d0c04c459fb1bc73a..793fb605399ac099863d27f5b43ea1fccfc35448 100644
--- a/third_party/WebKit/public/BUILD.gn
+++ b/third_party/WebKit/public/BUILD.gn
@@ -705,10 +705,7 @@ grit("image_resources") {
 }
 
 mojom("mojo_bindings") {
-  visibility = [
-    "//components/payments/content/*",

[jochen (gone - plz use gerrit), 2017/06/28 07:38:30]

why did you remove this?

[kpaulhamus, 2017/06/28 08:48:16]

John said it was no longer necessary, per his last comment. Ought I leave it for
payments team to remove?

-    "//content/*",
-  ]
+  visibility = [ "//content/*" ]
   visibility_blink = [
     "//content/common:mojo_bindings_blink",
     "//third_party/WebKit/Source/platform",
@@ -736,6 +733,7 @@ mojom("mojo_bindings") {
     "platform/modules/sensitive_input_visibility/sensitive_input_visibility_service.mojom",
     "platform/modules/serviceworker/service_worker_event_status.mojom",
     "platform/modules/serviceworker/service_worker_stream_handle.mojom",
+    "platform/modules/webauth/authenticator.mojom",
     "platform/modules/websockets/websocket.mojom",
     "platform/referrer.mojom",
     "platform/site_engagement.mojom",