Add WebAuthn bindings and client interface.

third_party/WebKit/Source/modules/webauth/ScopedCredentialOptions.idl

Index: third_party/WebKit/Source/modules/webauth/ScopedCredentialOptions.idl
diff --git a/third_party/WebKit/Source/modules/webauth/ScopedCredentialOptions.idl b/third_party/WebKit/Source/modules/webauth/ScopedCredentialOptions.idl
new file mode 100644
index 0000000000000000000000000000000000000000..1e2b39a16adc54da8ab7cfb2b16d70b6d3bb890b
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+++ b/third_party/WebKit/Source/modules/webauth/ScopedCredentialOptions.idl
@@ -0,0 +1,12 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// https://w3c.github.io/webauthn/#dictdef-scopedcredentialoptions
+
+dictionary ScopedCredentialOptions {
+    unsigned long timeoutSeconds;
+    USVString rpId;
+    sequence<ScopedCredentialDescriptor> excludeList;
+    AuthenticationExtensions extensions;
+};