Revert of DevTools: use explicit IPC messages for enabling/disabling tracing instead of intercepting protocol…

content/browser/devtools/devtools_tracing_handler.h

Index: content/browser/devtools/devtools_tracing_handler.h
diff --git a/content/browser/devtools/devtools_tracing_handler.h b/content/browser/devtools/devtools_tracing_handler.h
index fe270bd847264bd4eb3283885a8cf0bce90af6ae..20ebca8685022abc8990a45898fafbf50c6e5412 100644
--- a/content/browser/devtools/devtools_tracing_handler.h
+++ b/content/browser/devtools/devtools_tracing_handler.h
@@ -30,9 +30,6 @@
 
   void OnClientDetached();
 
-  void EnableTracing(const std::string& category_filter);
-  void DisableTracing();
-
  private:
   void BeginReadingRecordingResult(const base::FilePath& path);
   void ReadRecordingResult(const scoped_refptr<base::RefCountedString>& result);
@@ -47,6 +44,12 @@
 
   scoped_refptr<DevToolsProtocol::Response> OnGetCategories(
       scoped_refptr<DevToolsProtocol::Command> command);
+
+  void OnTracingStarted(
+      scoped_refptr<DevToolsProtocol::Notification> notification);
+
+  void OnTracingStopped(
+      scoped_refptr<DevToolsProtocol::Notification> notification);
 
   void OnCategoriesReceived(scoped_refptr<DevToolsProtocol::Command> command,
                             const std::set<std::string>& category_set);