Create a `TaskScheduler` when initializing run-as-node mode.

It fixes crashes when V8 tries to execute background tasks via the TaskScheduler.

atom/app/node_main.cc

@@ -12,6 +12,7 @@
 #include "atom/common/native_mate_converters/string16_converter.h"
 #include "base/command_line.h"
 #include "base/feature_list.h"
+#include "base/task_scheduler/task_scheduler.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "gin/array_buffer.h"
 #include "gin/public/isolate_holder.h"
@@ -40,6 +41,10 @@ int NodeMain(int argc, char *argv[]) {
 
     gin::V8Initializer::LoadV8Snapshot();
     gin::V8Initializer::LoadV8Natives();
+
+    // V8 requires a task scheduler apparently
+    base::TaskScheduler::CreateAndStartWithDefaultParams("Electron");
+
     JavascriptEnvironment gin_env;
 
     int exec_argc;
@@ -88,6 +93,13 @@ int NodeMain(int argc, char *argv[]) {
     node::FreeEnvironment(env);
   }
 
+  // According to "src/gin/shell/gin_main.cc":
+  //
+  // gin::IsolateHolder waits for tasks running in TaskScheduler in its
+  // destructor and thus must be destroyed before TaskScheduler starts skipping
+  // CONTINUE_ON_SHUTDOWN tasks.
+  base::TaskScheduler::GetInstance()->Shutdown();
+
   v8::V8::Dispose();
 
   return exit_code;