Http cache: Make sure that issuing a byte range request

net/http/http_cache_transaction.h

Index: net/http/http_cache_transaction.h
===================================================================
--- net/http/http_cache_transaction.h	(revision 148620)
+++ net/http/http_cache_transaction.h	(working copy)
@@ -326,6 +326,11 @@
   // working with range requests.
   int DoPartialCacheReadCompleted(int result);
 
+  // Restarts this transaction after deleting the cached data. It is meant to
+  // be used when the current request cannot be fulfilled due to conflicts
+  // between the byte range request and the cached entry.
+  int DoRestartPartialRequest();
+
   // Returns true if we should bother attempting to resume this request if it
   // is aborted while in progress. If |has_data| is true, the size of the stored
   // data is considered for the result.