Adding shutdown tracing capabilities

content/browser/browser_shutdown_profile_dumper.h

+// Copyright (c) 2013 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_BROWSER_SHUTDOWN_PROFILE_DUMPER_H_
+#define CONTENT_BROWSER_BROWSER_SHUTDOWN_PROFILE_DUMPER_H_
+
+#include <string>
+
+#include "base/basictypes.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/ref_counted_memory.h"
+#include "content/common/content_export.h"
+
+namespace base {
+class FilePath;
+}
+
+namespace content {
+
+// This class is intended to dump the tracing results of the shutdown process
+// to a file before the browser process exits.
+// It will save the file either into the command line passed
+// "--trace-shutdown-file=<name>" parameter - or - to "chrometrace.log".

[DaveMoore, 2013/09/03 17:02:48]

What directory is chrometrace.log located in?

[Mr4D (OOO till 08-26), 2013/09/03 17:34:34]

Added a comment. But following the way as startup tracing has done it.

+// Use the class with a scoped_ptr to automatically write the dump when the
+// object gets destroyed.
+// Note that we cannot use the asynchronous file writer since the
+// |SequencedWorkerPool| will get killed in the shutdown process.
+class BrowserShutdownProfileDumper {
+ public:
+  BrowserShutdownProfileDumper();
+
+  virtual ~BrowserShutdownProfileDumper();
+
+ private:
+  // Writes all traces which happened to disc.
+  void WriteTracesToDisc(base::FilePath file_name);
+
+  // Returns the file name where we should save the trace dump to.
+  base::FilePath GetFileName();
+
+  // The callback for the |TraceLog::Flush| function. It saves all traces to
+  // disc.
+  void WriteTraceDataCollected(
+      const scoped_refptr<base::RefCountedString>& events_str);
+
+  // Returns true if the dump file is valid.
+  bool IsFileValid();
+
+  // Writes a string to the dump file.
+  void WriteString(const std::string& string);
+
+  // Write a buffer to the dump file.
+  void WriteChars(const char* chars, size_t size);
+
+  // Closes the dump file.
+  void CloseFile();
+
+  // The number of blocks we have already written.
+  int blocks_;
+  // For dumping the content to disc.
+  FILE* dump_file_;
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_BROWSER_SHUTDOWN_PROFILE_DUMPER_H_