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

components/webauth/authenticator_impl.h

Index: components/webauth/authenticator_impl.h
diff --git a/components/webauth/authenticator_impl.h b/components/webauth/authenticator_impl.h
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+++ b/components/webauth/authenticator_impl.h
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+// Copyright 2017 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.
+
+#ifndef COMPONENTS_WEBAUTH_AUTHENTICATOR_IMPL_H_
+#define COMPONENTS_WEBAUTH_AUTHENTICATOR_IMPL_H_
+
+#include <vector>
+
+#include "base/macros.h"
+#include "content/public/browser/web_contents.h"
+#include "mojo/public/cpp/bindings/binding.h"
+#include "mojo/public/cpp/bindings/interface_request.h"
+#include "public/platform/modules/webauth/authenticator.mojom.h"
+
+namespace content {
+class RenderFrameHost;
+}
+
+namespace webauth {
+
+// Implementation of the public Authenticator interface.
+class AuthenticatorImpl : public mojom::Authenticator {
+ public:
+  static void Create(content::RenderFrameHost* render_frame_host,
+                     mojom::AuthenticatorRequest request);
+  ~AuthenticatorImpl() override;
+
+  void set_connection_error_handler(const base::Closure& error_handler) {
+    connection_error_handler_ = error_handler;
+  }
+
+ private:
+  AuthenticatorImpl(content::RenderFrameHost* render_frame_host);
+
+  // mojom:Authenticator
+  void MakeCredential(
+      mojom::RelyingPartyAccountPtr account,
+      std::vector<mojom::ScopedCredentialParametersPtr> parameters,
+      const std::vector<uint8_t>& challenge,
+      mojom::ScopedCredentialOptionsPtr options,
+      MakeCredentialCallback callback) override;
+
+  base::Closure connection_error_handler_;
+  base::CancelableClosure timeout_callback_;
+  url::Origin caller_origin_;
+  DISALLOW_COPY_AND_ASSIGN(AuthenticatorImpl);
+};
+
+}  // namespace webauth
+
+#endif  // COMPONENTS_WEBAUTH_AUTHENTICATOR_IMPL_H_