Disk cache: First pass to make it possible to have...

net/disk_cache/trace.h

 // Copyright (c) 2006-2008 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.
 
 // This file provides support for basic in-memory tracing of short events. We
 // keep a static circular buffer where we store the last traced events, so we
 // can review the cache recent behavior should we need it.
 
 #ifndef NET_DISK_CACHE_TRACE_H__
 #define NET_DISK_CACHE_TRACE_H__
 
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
+#include "base/ref_counted.h"
 
 namespace disk_cache {
 
 // Create and destroy the tracing buffer.
-bool InitTrace(void);
+void InitTrace(void);
 void DestroyTrace(void);
 
-// Simple class to handle the trace buffer lifetime.
-class TraceObject {
+// Simple class to handle the trace buffer lifetime. Any object interested in
+// tracing should keep a reference to the object returned by GetTraceObject().
+class TraceObject : public base::RefCounted<TraceObject> {
+  friend class base::RefCounted<TraceObject>;
  public:
+  static TraceObject* GetTraceObject();
+
+ private:
   TraceObject() {
     InitTrace();
   }
+
   ~TraceObject() {
     DestroyTrace();
   }
-
- private:
   DISALLOW_EVIL_CONSTRUCTORS(TraceObject);
 };
 
 // Traces to the internal buffer.
 void Trace(const char* format, ...);
 
 }  // namespace disk_cache
 
 #endif  // NET_DISK_CACHE_TRACE_H__