Add WebAuthn bindings and client interface.

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

Index: third_party/WebKit/Source/modules/webauth/ScopedCredentialInfo.idl
diff --git a/third_party/WebKit/Source/modules/webauth/ScopedCredentialInfo.idl b/third_party/WebKit/Source/modules/webauth/ScopedCredentialInfo.idl
new file mode 100644
index 0000000000000000000000000000000000000000..87e15a2b5be69d82e907c1cc1a5cb6e9a90a4bd8
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+++ b/third_party/WebKit/Source/modules/webauth/ScopedCredentialInfo.idl
@@ -0,0 +1,13 @@
+// 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/#scopedcredentialinfo
+
+[
+    RuntimeEnabled=WebAuth,
+    SecureContext
+] interface ScopedCredentialInfo {
+    readonly attribute ArrayBuffer clientData;
+    readonly attribute ArrayBuffer attestation;
+};