Implement exponential back-off mechanism and enforce it at the URLRequestHttpJob level.

net/url_request/request_throttler_header_adapter.h

+// Copyright (c) 2010 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 NET_URL_REQUEST_REQUEST_THROTTLER_HEADER_ADAPTER_H_
+#define NET_URL_REQUEST_REQUEST_THROTTLER_HEADER_ADAPTER_H_
+
+#include <string>
+
+#include "base/scoped_ptr.h"
+#include "net/http/http_response_headers.h"
+#include "net/url_request/request_throttler_header_interface.h"
+
+// Adapter for the HTTP header interface of the request throttler component.
+class RequestThrottlerHeaderAdapter : public RequestThrottlerHeaderInterface {
+ public:
+  explicit RequestThrottlerHeaderAdapter(
+      const scoped_refptr<net::HttpResponseHeaders>& headers);

[willchan no longer on Chromium, 2010/11/17 20:32:34]

http://groups.google.com/a/chromium.org/group/chromium-dev/browse_thread/thre...
says to pass in the raw pointer here.

[yzshen, 2010/11/19 23:51:36]

Done. Thanks!

+  virtual ~RequestThrottlerHeaderAdapter() {}
+
+  // Implementation of RequestThrottlerHeaderInterface
+  virtual std::string GetNormalizedValue(const std::string& key) const;
+  virtual int GetResponseCode() const;
+ private:
+  const scoped_refptr<net::HttpResponseHeaders> response_header_;
+};
+
+#endif  // NET_URL_REQUEST_REQUEST_THROTTLER_HEADER_ADAPTER_H_