revert is_sparse_ "simplification"

net/http/http_cache_transaction.cc

 // Copyright (c) 2012 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.
 
 #include "net/http/http_cache_transaction.h"
 
 #include "build/build_config.h"  // For OS_POSIX
 
 #if defined(OS_POSIX)
 #include <unistd.h>
@@ skipping 309 matching lines @@
   // avoid writing again (it should be the same, right?), but let's allow the
   // caller to "update" the contents with something new.
   return entry_->disk_entry->WriteData(kMetadataIndex, 0, buf, buf_len,
                                        callback, true);
 }
 
 bool HttpCache::Transaction::AddTruncatedFlag() {
   DCHECK(mode_ & WRITE || mode_ == NONE);
 
   // Don't set the flag for sparse entries.
-  if (is_sparse_)
+  if (partial_ && !truncated_)
     return true;
 
   if (!CanResume(true))
     return false;
 
   // We may have received the whole resource already.
   if (done_reading_)
     return true;
 
   truncated_ = true;
@@ skipping 2577 matching lines @@
     default:
       NOTREACHED();
   }
 }
 
 void HttpCache::Transaction::OnIOComplete(int result) {
   DoLoop(result);
 }
 
 }  // namespace net