Add a Content API around TracingController.

content/browser/trace_subscriber_stdio.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 "content/browser/trace_subscriber_stdio.h"
 
 #include "base/bind.h"
+#include "base/debug/trace_event.h"
 #include "base/logging.h"
 #include "base/threading/sequenced_worker_pool.h"
 #include "content/public/browser/browser_thread.h"
 
 namespace content {
 
 // All method calls on this class are done on a SequencedWorkerPool thread.
 class TraceSubscriberStdioImpl
     : public base::RefCountedThreadSafe<TraceSubscriberStdioImpl> {
  public:
@@ skipping 71 matching lines @@
 }
 
 void TraceSubscriberStdio::OnTraceDataCollected(
     const scoped_refptr<base::RefCountedString>& data_ptr) {
   BrowserThread::PostBlockingPoolSequencedTask(
       __FILE__, FROM_HERE,
       base::Bind(&TraceSubscriberStdioImpl::OnData, impl_.get(), data_ptr));
 }
 
 }  // namespace content
-