Use TracingController for startup tracing

content/browser/browser_main_loop.h

Index: content/browser/browser_main_loop.h
diff --git a/content/browser/browser_main_loop.h b/content/browser/browser_main_loop.h
index 84b31b46e524a10adc3e81fe569802538e1fd704..445d99050ef17eaf837379c2bcc81301fa29c69b 100644
--- a/content/browser/browser_main_loop.h
+++ b/content/browser/browser_main_loop.h
@@ -14,6 +14,7 @@
 class CommandLine;
 
 namespace base {
+class FilePath;
 class HighResolutionTimerManager;
 class MessageLoop;
 class PowerMonitor;
@@ -98,6 +99,8 @@ class CONTENT_EXPORT BrowserMainLoop {
   media::MIDIManager* midi_manager() const { return midi_manager_.get(); }
   base::Thread* indexed_db_thread() const { return indexed_db_thread_.get(); }
 
+  bool is_tracing_startup() const { return is_tracing_startup_; }
+
  private:
   class MemoryObserver;
   // For ShutdownThreadsAndCleanUp.
@@ -118,6 +121,9 @@ class CONTENT_EXPORT BrowserMainLoop {
 
   void MainMessageLoopRun();
 
+  void InitStartupTracing(const CommandLine& command_line);
+  void EndStartupTracing(const base::FilePath& trace_file);
+
   // Members initialized on construction ---------------------------------------
   const MainFunctionParams& parameters_;
   const CommandLine& parsed_command_line_;
@@ -173,6 +179,8 @@ class CONTENT_EXPORT BrowserMainLoop {
   scoped_ptr<base::debug::TraceMemoryController> trace_memory_controller_;
   scoped_ptr<base::debug::TraceEventSystemStatsMonitor> system_stats_monitor_;
 
+  bool is_tracing_startup_;
+
   DISALLOW_COPY_AND_ASSIGN(BrowserMainLoop);
 };