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

components/webauth/authenticator.mojom

Index: components/webauth/authenticator.mojom
diff --git a/components/webauth/authenticator.mojom b/components/webauth/authenticator.mojom
index 7f8ba4a742181b207e6de4cef7641ccea2377dd0..818c4a0e902ec6e0edcc284e89f075ccdc88243b 100644
--- a/components/webauth/authenticator.mojom
+++ b/components/webauth/authenticator.mojom
@@ -5,18 +5,32 @@
 [JavaPackage="org.chromium.webauth.mojom"]
 module webauth.mojom;
 
+enum AuthenticatorStatus {
+  SUCCESS,
+  CANCELLED,
+  UNKNOWN_ERROR,
+  NOT_ALLOWED_ERROR,
+  NOT_SUPPORTED_ERROR,
+  SECURITY_ERROR,
+};
+
 struct ScopedCredentialInfo {
   array<uint8> client_data;
   array<uint8> attestation;
 };
 
 struct RelyingPartyAccount {
+  // Friendly name of the Relying Party, e.g. "Acme Corporation"
   string rp_display_name;
+  // Friendly name associated with the user account, e.g. "John P. Smith"
   string display_name;
-  string id;
-  string name;
+  // Identifier for the account, corresponding to no more than one credential 
+  // per authenticator and Relying Party.
+  string id; 
+  // Detailed name for the account, e.g. john.p.smith@example.com
+  string? name;
   // TODO(kpaulhamus): Make this url.mojom.Url in followup CL
-  string image_url;
+  string? image_url;
 };
 
 struct ScopedCredentialParameters {
@@ -25,9 +39,9 @@ struct ScopedCredentialParameters {
 };
 
 struct ScopedCredentialOptions {
-  // TODO(kpaulhamus): Make this mojo.common.mojom.TimeDelta in followup CL
-  uint32 timeout_seconds;
-  string rp_id;
+  //TODO(kpaulhamus): Make this mojo.common.mojom.TimeDelta in followup CL
+  double adjusted_timeout;
+  string? rp_id;
   array<ScopedCredentialDescriptor> exclude_list;
   // TODO(kpaulhamus): add Extensions
 };
@@ -48,10 +62,13 @@ enum Transport {
   BLE,
 };
 
+// TODO add comments everywhere
+// |account_information|:  
 interface Authenticator {
-  makeCredential(RelyingPartyAccount account_information,
+  MakeCredential(RelyingPartyAccount account_information,
                  array<ScopedCredentialParameters> crypto_parameters,
                  array<uint8> attestation_challenge,
-                 ScopedCredentialOptions? options)
-      => (array<ScopedCredentialInfo> scoped_credentials);
+                 ScopedCredentialOptions options)
+      => (AuthenticatorStatus status, 
+          ScopedCredentialInfo? scoped_credential);
 };