[Tracing] Use TracingCategoryObserver in runtime statistics

src/d8.cc

 // Copyright 2012 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 <errno.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/stat.h>
 
 #include <algorithm>
@@ skipping 2813 matching lines @@
   std::unique_ptr<platform::tracing::TracingController> tracing_controller;
   if (options.trace_enabled) {
     trace_file.open("v8_trace.json");
     tracing_controller.reset(new platform::tracing::TracingController());
     platform::tracing::TraceBuffer* trace_buffer =
         platform::tracing::TraceBuffer::CreateTraceBufferRingBuffer(
             platform::tracing::TraceBuffer::kRingBufferChunks,
             platform::tracing::TraceWriter::CreateJSONTraceWriter(trace_file));
     tracing_controller->Initialize(trace_buffer);
     if (!i::FLAG_verify_predictable) {
-      platform::SetTracingController(g_platform, tracing_controller.get());
-      tracing_controller.release();
+      platform::SetTracingController(g_platform, tracing_controller.release());
     }
   }
 
   v8::V8::InitializePlatform(g_platform);
   v8::V8::Initialize();
   if (options.natives_blob || options.snapshot_blob) {
     v8::V8::InitializeExternalStartupData(options.natives_blob,
                                           options.snapshot_blob);
   } else {
     v8::V8::InitializeExternalStartupData(argv[0]);
@@ skipping 111 matching lines @@
 }
 
 }  // namespace v8
 
 
 #ifndef GOOGLE3
 int main(int argc, char* argv[]) {
   return v8::Shell::Main(argc, argv);
 }
 #endif