[Tracing] V8 Tracing Controller - Fix async trace event bug

src/libplatform/tracing/trace-writer.cc

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/libplatform/tracing/trace-writer.h"
 
 #include <cmath>
 
 #include "base/trace_event/common/trace_event_common.h"
 #include "src/base/platform/platform.h"
@@ skipping 89 matching lines @@
           << TracingController::GetCategoryGroupName(
                  trace_event->category_enabled_flag())
           << "\",\"name\":\"" << trace_event->name()
           << "\",\"dur\":" << trace_event->duration()
           << ",\"tdur\":" << trace_event->cpu_duration();
   if (trace_event->flags() & TRACE_EVENT_FLAG_HAS_ID) {
     if (trace_event->scope() != nullptr) {
       stream_ << ",\"scope\":\"" << trace_event->scope() << "\"";
     }
     // So as not to lose bits from a 64-bit integer, output as a hex string.
-    stream_ << ",\"id\":\"0x" << std::hex << trace_event->id() << "\"";
+    stream_ << ",\"id\":\"0x" << std::hex << trace_event->id() << "\""
+            << std::dec;
   }
   stream_ << ",\"args\":{";
   const char** arg_names = trace_event->arg_names();
   const uint8_t* arg_types = trace_event->arg_types();
   TraceObject::ArgValue* arg_values = trace_event->arg_values();
   for (int i = 0; i < trace_event->num_args(); ++i) {
     if (i > 0) stream_ << ",";
     stream_ << "\"" << arg_names[i] << "\":";
     AppendArgValue(arg_types[i], arg_values[i]);
   }
   stream_ << "}}";
   // TODO(fmeawad): Add support for Flow Events.
 }
 
 void JSONTraceWriter::Flush() {}
 
 TraceWriter* TraceWriter::CreateJSONTraceWriter(std::ostream& stream) {
   return new JSONTraceWriter(stream);
 }
 
 }  // namespace tracing
 }  // namespace platform
 }  // namespace v8