Release the cache entry on deferred redirect.

net/http/http_transaction.h

 // Copyright (c) 2011 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_HTTP_HTTP_TRANSACTION_H_
 #define NET_HTTP_HTTP_TRANSACTION_H_
 
 #include "net/base/completion_callback.h"
 #include "net/base/load_states.h"
 #include "net/base/net_export.h"
@@ skipping 91 matching lines @@
   // it.  (Right now, this is only network transactions, not cache ones.)
   //
   // Returns true and overwrites headers if it can get the request headers;
   // otherwise, returns false and does not modify headers.
   virtual bool GetFullRequestHeaders(HttpRequestHeaders* headers) const = 0;
 
   // Called to tell the transaction that we have successfully reached the end
   // of the stream. This is equivalent to performing an extra Read() at the end
   // that should return 0 bytes. This method should not be called if the
   // transaction is busy processing a previous operation (like a pending Read).
+  // This is used to inform the cache that the response was not canceled
+  // prematurely.
+  //
+  // DoneReading may also be called before the first Read() to notify that the
+  // entire response body is to be ignored (e.g., in a redirect).
   virtual void DoneReading() = 0;
 
   // Returns the response info for this transaction or NULL if the response
   // info is not available.
   virtual const HttpResponseInfo* GetResponseInfo() const = 0;
 
   // Returns the load state for this transaction.
   virtual LoadState GetLoadState() const = 0;
 
   // Returns the upload progress in bytes.  If there is no upload data,
   // zero will be returned.  This does not include the request headers.
   virtual UploadProgress GetUploadProgress() const = 0;
 
   // Populates all of load timing, except for request start times and receive
   // headers time.
   // |load_timing_info| must have all null times when called.  Returns false and
   // does not modify |load_timing_info| if there's no timing information to
   // provide.
   virtual bool GetLoadTimingInfo(LoadTimingInfo* load_timing_info) const = 0;
 
   // Called when the priority of the parent job changes.
   virtual void SetPriority(RequestPriority priority) = 0;
 };
 
 }  // namespace net
 
 #endif  // NET_HTTP_HTTP_TRANSACTION_H_