[Tracing] Fix crash of --enable-tracing.

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 2793 matching lines @@
   _CrtSetReportFile(_CRT_ERROR, _CRTDBG_FILE_STDERR);
   _set_error_mode(_OUT_TO_STDERR);
 #endif  // defined(_MSC_VER)
 #endif  // defined(_WIN32) || defined(_WIN64)
   if (!SetOptions(argc, argv)) return 1;
   v8::V8::InitializeICUDefaultLocation(argv[0], options.icu_data_file);
   g_platform = i::FLAG_verify_predictable
                    ? new PredictablePlatform()
                    : v8::platform::CreateDefaultPlatform();
 
-  std::unique_ptr<platform::tracing::TracingController> tracing_controller;
+  platform::tracing::TracingController* tracing_controller;
   if (options.trace_enabled) {
     trace_file.open("v8_trace.json");
-    tracing_controller.reset(new platform::tracing::TracingController());
+    tracing_controller = 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.release());
+      platform::SetTracingController(g_platform, tracing_controller);
     }
   }
 
   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 99 matching lines @@
   // Dump basic block profiling data.
   if (i::BasicBlockProfiler* profiler =
           reinterpret_cast<i::Isolate*>(isolate)->basic_block_profiler()) {
     i::OFStream os(stdout);
     os << *profiler;
   }
   isolate->Dispose();
   V8::Dispose();
   V8::ShutdownPlatform();
   delete g_platform;
+  if (i::FLAG_verify_predictable) {
+    delete tracing_controller;
+  }
 
   return result;
 }
 
 }  // namespace v8
 
 
 #ifndef GOOGLE3
 int main(int argc, char* argv[]) {
   return v8::Shell::Main(argc, argv);
 }
 #endif