Revert of [tracing] Support ConvertableToTraceFormat argument type.

src/libplatform/tracing/trace-object.cc

Index: src/libplatform/tracing/trace-object.cc
diff --git a/src/libplatform/tracing/trace-object.cc b/src/libplatform/tracing/trace-object.cc
index bb4bf7139075136c01e442b13088d3ec57584dc7..55be8921cb66d46669561ca233f68862bdcdfb2d 100644
--- a/src/libplatform/tracing/trace-object.cc
+++ b/src/libplatform/tracing/trace-object.cc
@@ -5,7 +5,6 @@
 #include "include/libplatform/v8-tracing.h"
 
 #include "base/trace_event/common/trace_event_common.h"
-#include "include/v8-platform.h"
 #include "src/base/platform/platform.h"
 #include "src/base/platform/time.h"
 
@@ -31,13 +30,11 @@
   }
 }
 
-void TraceObject::Initialize(
-    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) {
+void TraceObject::Initialize(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, unsigned int flags) {
   pid_ = base::OS::GetCurrentProcessId();
   tid_ = base::OS::GetCurrentThreadId();
   phase_ = phase;
@@ -58,8 +55,6 @@
     arg_names_[i] = arg_names[i];
     arg_values_[i].as_uint = arg_values[i];
     arg_types_[i] = arg_types[i];
-    if (arg_types[i] == TRACE_VALUE_TYPE_CONVERTABLE)
-      arg_convertables_[i] = std::move(arg_convertables[i]);
   }
 
   bool copy = !!(flags & TRACE_EVENT_FLAG_COPY);
@@ -112,10 +107,8 @@
     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, int pid, int tid, int64_t ts, int64_t tts,
-    uint64_t duration, uint64_t cpu_duration) {
+    const uint64_t* arg_values, unsigned int flags, int pid, int tid,
+    int64_t ts, int64_t tts, uint64_t duration, uint64_t cpu_duration) {
   pid_ = pid;
   tid_ = tid;
   phase_ = phase;