Disk Cache: Fix the value reported for QuickListCheck histogram.

net/disk_cache/rankings.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/disk_cache/rankings.h"
 
 #include "base/metrics/histogram.h"
 #include "net/disk_cache/backend_impl.h"
 #include "net/disk_cache/entry_impl.h"
 #include "net/disk_cache/errors.h"
@@ skipping 888 matching lines @@
       return ERR_INVALID_TAIL;
     }
   } while (current != end1 && current != end2);
   return ERR_NO_ERROR;
 }
 
 // TODO(rvargas): remove when we figure why we have corrupt heads.
 void Rankings::QuickListCheck() {
   for (int i = 0; i < LAST_ELEMENT; i++) {
     int rv = CheckHeadAndTail(static_cast<List>(i));
-    CACHE_UMA(CACHE_ERROR, "QuickListCheck", 0, rv);
+    CACHE_UMA(CACHE_ERROR, "QuickListCheck", 0, rv * -1);
   }
 }
 
 int Rankings::CheckHeadAndTail(List list) {
   Addr head_addr = heads_[list];
   Addr tail_addr = tails_[list];
 
   if (!head_addr.is_initialized() && !tail_addr.is_initialized())
     return ERR_NO_ERROR;
 
@@ skipping 85 matching lines @@
 void Rankings::DecrementCounter(List list) {
   if (!count_lists_)
     return;
 
   DCHECK(control_data_->sizes[list] > 0);
   if (control_data_->sizes[list] > 0)
     control_data_->sizes[list]--;
 }
 
 }  // namespace disk_cache