Add a mode flag to the tracing framework.

content/browser/devtools/devtools_tracing_handler.h

 // 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.
 
 #ifndef CONTENT_BROWSER_DEVTOOLS_DEVTOOLS_TRACING_HANDLER_H_
 #define CONTENT_BROWSER_DEVTOOLS_DEVTOOLS_TRACING_HANDLER_H_
 
+#include "base/debug/trace_event.h"
 #include "content/browser/devtools/devtools_protocol.h"
 #include "content/public/browser/trace_subscriber.h"
 
 namespace content {
 
 class DevToolsWebSocketSender;
 
 // This class bridges DevTools remote debugging server with the trace
 // infrastructure.
 class DevToolsTracingHandler
     : public TraceSubscriber,
       public DevToolsProtocol::Handler {
  public:
   static const char kDomain[];
 
   DevToolsTracingHandler();
   virtual ~DevToolsTracingHandler();
 
   // TraceSubscriber:
   virtual void OnEndTracingComplete() OVERRIDE;;
   virtual void OnTraceDataCollected(
       const scoped_refptr<base::RefCountedString>& trace_fragment) OVERRIDE;
 
  private:
   scoped_ptr<DevToolsProtocol::Response> OnStart(
       DevToolsProtocol::Command* command);
   scoped_ptr<DevToolsProtocol::Response> OnEnd(
       DevToolsProtocol::Command* command);
 
+  base::debug::TraceLog::Options TraceOptionsFromString(
+      const std::string& options);
+
   bool is_running_;
 
   DISALLOW_COPY_AND_ASSIGN(DevToolsTracingHandler);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_DEVTOOLS_DEVTOOLS_TRACING_HANDLER_H_