HTTP retry support.

net/http/http_network_transaction.h

Index: net/http/http_network_transaction.h
diff --git a/net/http/http_network_transaction.h b/net/http/http_network_transaction.h
index 895ecc3d17af64fb6b8ade42ce7e2324a824aca1..7d913ab124ad055b67ea1ddf6b138062bef8e0aa 100644
--- a/net/http/http_network_transaction.h
+++ b/net/http/http_network_transaction.h
@@ -190,6 +190,9 @@ class NET_EXPORT_PRIVATE HttpNetworkTransaction
   // Record histogram of latency (durations until last byte received).
   void LogTransactionMetrics() const;
 
+  // Record histogram of retry attempt success rate.
+  void LogTransactionRetryMetrics(int error) const;
+
   // Writes a log message to help debugging in the field when we block a proxy
   // response to a CONNECT request.
   void LogBlockedTunnelResponse(int response_code) const;
@@ -316,6 +319,25 @@ class NET_EXPORT_PRIVATE HttpNetworkTransaction
   // Total number of bytes received on streams for this transaction.
   int64 total_received_bytes_;
 
+  // Total number of retries for this transaction.
+  int retry_attempt_;
+
+  // How much data was read from a response body before retrying a transaction.
+  int64 offset_;
+
+  // Previous content length, used for retry.
+  int64 previous_content_length_;
+
+  // Previous etag, used for retry.
+  std::string previous_etag_;
+
+  // Previous last modified, used for retry.
+  std::string previous_last_modified_;
+
+  // Hash of previous request attempt for cross-checking when retrying without
+  // range support.
+  uint8 hash_[8];
+
   // The time the Start method was called.
   base::Time start_time_;