Revert 123140 - Use SequencedWorkerPool for disk operations in TraceSubscriberStdio.

content/browser/trace_subscriber_stdio.h

-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// 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"
 #include "content/common/content_export.h"
 
-namespace content {
-
-class TraceSubscriberStdioImpl;
-
 // Stdio implementation of TraceSubscriber. Use this to write traces to a file.
 class CONTENT_EXPORT TraceSubscriberStdio : public TraceSubscriber {
  public:
+  TraceSubscriberStdio();
   // Creates or overwrites the specified file. Check IsValid() for success.
   explicit TraceSubscriberStdio(const FilePath& path);
-  virtual ~TraceSubscriberStdio();
+
+  // Creates or overwrites the specified file. Returns true on success.
+  bool OpenFile(const FilePath& path);
+  // Finishes json output and closes file.
+  void CloseFile();
+
+  // Returns TRUE if we're currently writing data to a file.
+  bool IsValid();
 
   // Implementation of TraceSubscriber
   virtual void OnEndTracingComplete() OVERRIDE;
-  virtual void OnTraceDataCollected(
-      const scoped_refptr<base::RefCountedString>& data_ptr) OVERRIDE;
+  virtual void OnTraceDataCollected(const std::string& trace_fragment) OVERRIDE;
+
+  virtual ~TraceSubscriberStdio();
 
  private:
-  scoped_refptr<TraceSubscriberStdioImpl> impl_;
+  void Write(const std::string& output_str);
+
+  FILE* file_;
+  base::debug::TraceResultBuffer trace_buffer_;
 };
 
-}  // namespace content
-
 #endif  // CONTENT_BROWSER_TRACE_SUBSCRIBER_STDIO_H_