ash: Support closing in-session auth dialog from dbus

The platform side may want to close the in-session auth dialog (for
example in WebAuthn when the browser issues a timeout). Expose a
DBus API for dismissing the dialog. This will have the same effect
as if the user clicks the Cancel button.

Change-Id: I9ab2456967d08c382302ee528b0aa6cc2a0d01c5
Bug: b/167574666
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2499180Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Yicheng Li <yichengli@chromium.org>
Cr-Commit-Position: refs/heads/master@{#827370}

ash/dbus/user_authentication_service_provider.cc

@@ -29,6 +29,13 @@ void UserAuthenticationServiceProvider::Start(
                           weak_ptr_factory_.GetWeakPtr()),
       base::BindOnce(&UserAuthenticationServiceProvider::OnExported,
                      weak_ptr_factory_.GetWeakPtr()));
+  exported_object->ExportMethod(
+      chromeos::kUserAuthenticationServiceInterface,
+      chromeos::kUserAuthenticationServiceCancelMethod,
+      base::BindRepeating(&UserAuthenticationServiceProvider::Cancel,
+                          weak_ptr_factory_.GetWeakPtr()),
+      base::BindOnce(&UserAuthenticationServiceProvider::OnExported,
+                     weak_ptr_factory_.GetWeakPtr()));
 }
 
 void UserAuthenticationServiceProvider::OnExported(
@@ -93,4 +100,13 @@ void UserAuthenticationServiceProvider::OnAuthFlowComplete(
   std::move(response_sender).Run(std::move(response));
 }
 
+void UserAuthenticationServiceProvider::Cancel(
+    dbus::MethodCall* method_call,
+    dbus::ExportedObject::ResponseSender response_sender) {
+  InSessionAuthDialogController::Get()->Cancel();
+  std::unique_ptr<dbus::Response> response =
+      dbus::Response::FromMethodCall(method_call);
+  std::move(response_sender).Run(std::move(response));
+}
+
 }  // namespace ash

ash/dbus/user_authentication_service_provider.h

@@ -46,6 +46,11 @@ class UserAuthenticationServiceProvider
                           dbus::ExportedObject::ResponseSender response_sender,
                           bool success);
 
+  // Called on UI thread in response to D-Bus requests. Dismisses the dialog if
+  // it's shown.
+  void Cancel(dbus::MethodCall* method_call,
+              dbus::ExportedObject::ResponseSender response_sender);
+
   // Keep this last so that all weak pointers will be invalidated at the
   // beginning of destruction.
   base::WeakPtrFactory<UserAuthenticationServiceProvider> weak_ptr_factory_{