Thread-local trace-event buffers

content/browser/tracing/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/tracing/trace_subscriber_stdio.h"
 
 #include "base/bind.h"
 #include "base/debug/trace_event.h"
 #include "base/file_util.h"
 #include "base/logging.h"
@@ skipping 28 matching lines @@
 
     LOG(INFO) << "Logging performance trace to file: " << path_.value();
     if (file_type_ == FILE_TYPE_PROPERTY_LIST)
       WriteString("{\"traceEvents\":");
     WriteString("[");
   }
 
   void OnTraceData(const scoped_refptr<base::RefCountedString>& data_ptr) {
     if (!IsValid())
       return;
+    DCHECK(!data_ptr->data().empty());
     if (needs_comma_)
       WriteString(",");
     WriteString(data_ptr->data());
     needs_comma_ = true;
   }
 
   void OnSystemTraceData(
       const scoped_refptr<base::RefCountedString>& data_ptr) {
     if (wrote_trace_) {
       WriteSystemTrace(data_ptr);
@@ skipping 132 matching lines @@
 void TraceSubscriberStdio::OnEndSystemTracing(
     const scoped_refptr<base::RefCountedString>& events_str_ptr) {
   BrowserThread::PostBlockingPoolSequencedTask(
       __FILE__, FROM_HERE,
       base::Bind(&TraceSubscriberStdioWorker::OnSystemTraceData,
                  worker_,
                  events_str_ptr));
 }
 
 }  // namespace content