Make idle tasks optional in the default platform.

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 2874 matching lines @@
   _CrtSetReportFile(_CRT_ASSERT, _CRTDBG_FILE_STDERR);
   _CrtSetReportMode(_CRT_ERROR, _CRTDBG_MODE_DEBUG | _CRTDBG_MODE_FILE);
   _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();
+                   : v8::platform::CreateDefaultPlatform(
+                         0, v8::platform::IdleTaskSupport::kEnabled);
 
   platform::tracing::TracingController* tracing_controller;
   if (options.trace_enabled) {
     trace_file.open("v8_trace.json");
     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);
@@ skipping 119 matching lines @@
 }
 
 }  // namespace v8
 
 
 #ifndef GOOGLE3
 int main(int argc, char* argv[]) {
   return v8::Shell::Main(argc, argv);
 }
 #endif