TraceSubscriber implementation that writes to a file.

content/browser/trace_subscriber_stdio.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 CONTENT_BROWSER_TRACE_SUBSCRIBER_STDIO_H_
+#define CONTENT_BROWSER_TRACE_SUBSCRIBER_STDIO_H_
+#pragma once
+
+#include <string>
+
+#include "base/file_util.h"
+#include "content/browser/trace_controller.h"
+
+// Stdio implementation of TraceSubscriber. Use this to write traces to a file.
+class TraceSubscriberStdio : public TraceSubscriber {
+ public:
+  // Creates or overwrites the specified file. Check IsValid() for success.
+  explicit TraceSubscriberStdio(const FilePath& path);
+
+  // Returns TRUE if we're currently writing data to a file.
+  bool IsValid();
+
+  // Implementation of TraceSubscriber
+  virtual void OnEndTracingComplete();
+  virtual void OnTraceDataCollected(const std::string& json_events);
+
+  virtual ~TraceSubscriberStdio();
+
+ private:
+  FILE* m_file;

[jam, 2011/06/22 02:40:49]

hi, i just saw this in another change.  we don't use hungarian notation.  this
should be file_

+};
+
+#endif  // CONTENT_BROWSER_TRACE_SUBSCRIBER_STDIO_H_