Create a Delayed Response Provider for GCDWebServer.

ios/web/public/test/response_providers/delayed_response_provider.h

+// 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.
+
+#ifndef IOS_WEB_PUBLIC_TEST_RESPONSE_PROVIDERS_DELAYED_RESPONSE_PROVIDER_H_
+#define IOS_WEB_PUBLIC_TEST_RESPONSE_PROVIDERS_DELAYED_RESPONSE_PROVIDER_H_
+
+#include <memory>
+
+#include "ios/web/public/test/response_providers/response_provider.h"
+
+namespace web {
+
+// A Response provider that delays the response provided by another reponse
+// provider
+class DelayedResponseProvider : public ResponseProvider {
+ public:
+  // Creates a DelayedResponseProvider that delays the response from
+  // |delayed_provider| by |delay| seconds.
+  DelayedResponseProvider(
+      std::unique_ptr<web::ResponseProvider> delayed_provider,
+      double delay);
+  ~DelayedResponseProvider() override;
+
+  // Forwards to |delayed_provider_|.
+  bool CanHandleRequest(const Request& request) override;
+
+  // Creates a GCDWebServerResponse that will proxy the object returned by
+  // Forwards to |delayed_provider_->GetGCDWebServerResponse(request)|.
+  // The read operation will be delayed by |delay_| seconds.
+  GCDWebServerResponse* GetGCDWebServerResponse(
+      const Request& request) override;
+
+ private:
+  std::unique_ptr<web::ResponseProvider> delayed_provider_;
+  double delay_;
+
+  DISALLOW_COPY_AND_ASSIGN(DelayedResponseProvider);
+};
+
+}  // namespace web
+
+#endif  // IOS_WEB_PUBLIC_TEST_RESPONSE_PROVIDERS_DELAYED_RESPONSE_PROVIDER_H_