Revert of [tracing] Support ConvertableToTraceFormat argument type.

src/libplatform/tracing/tracing-controller.cc

Index: src/libplatform/tracing/tracing-controller.cc
diff --git a/src/libplatform/tracing/tracing-controller.cc b/src/libplatform/tracing/tracing-controller.cc
index 92a8515823ceb4ef552b7f0e79bc94126fa5a30e..e9a21725e289fd565391084a0b933a00c82df407 100644
--- a/src/libplatform/tracing/tracing-controller.cc
+++ b/src/libplatform/tracing/tracing-controller.cc
@@ -46,15 +46,13 @@
     char phase, const uint8_t* category_enabled_flag, const char* name,
     const char* scope, uint64_t id, uint64_t bind_id, int num_args,
     const char** arg_names, const uint8_t* arg_types,
-    const uint64_t* arg_values,
-    std::unique_ptr<v8::ConvertableToTraceFormat>* arg_convertables,
-    unsigned int flags) {
+    const uint64_t* arg_values, unsigned int flags) {
   uint64_t handle;
   TraceObject* trace_object = trace_buffer_->AddTraceEvent(&handle);
   if (trace_object) {
     trace_object->Initialize(phase, category_enabled_flag, name, scope, id,
                              bind_id, num_args, arg_names, arg_types,
-                             arg_values, arg_convertables, flags);
+                             arg_values, flags);
   }
   return handle;
 }