Revert of Use TaskScheduler instead of WorkerPool in v8_platform.cc.

gin/shell/gin_main.cc

Index: gin/shell/gin_main.cc
diff --git a/gin/shell/gin_main.cc b/gin/shell/gin_main.cc
index 08703a4486889c816c20f8c204085c5b8447cbd8..c7cf598756d8538415970900911efa9b264401d4 100644
--- a/gin/shell/gin_main.cc
+++ b/gin/shell/gin_main.cc
@@ -14,8 +14,6 @@
 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "base/single_thread_task_runner.h"
-#include "base/sys_info.h"
-#include "base/task_scheduler/task_scheduler.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "gin/array_buffer.h"
 #include "gin/modules/console.h"
@@ -75,44 +73,34 @@ int main(int argc, char** argv) {
 #endif
 
   base::MessageLoop message_loop;
-  base::TaskScheduler::CreateAndSetSimpleTaskScheduler(
-      base::SysInfo::NumberOfProcessors());
 
   // Initialize the base::FeatureList since IsolateHolder can depend on it.
   base::FeatureList::SetInstance(base::WrapUnique(new base::FeatureList));
 
+  gin::IsolateHolder::Initialize(gin::IsolateHolder::kStrictMode,
+                                 gin::IsolateHolder::kStableV8Extras,
+                                 gin::ArrayBufferAllocator::SharedInstance());
+  gin::IsolateHolder instance(base::ThreadTaskRunnerHandle::Get());
+
+  gin::GinShellRunnerDelegate delegate;
+  gin::ShellRunner runner(&delegate, instance.isolate());
+
   {
-    gin::IsolateHolder::Initialize(gin::IsolateHolder::kStrictMode,
-                                   gin::IsolateHolder::kStableV8Extras,
-                                   gin::ArrayBufferAllocator::SharedInstance());
-    gin::IsolateHolder instance(base::ThreadTaskRunnerHandle::Get());
-
-    gin::GinShellRunnerDelegate delegate;
-    gin::ShellRunner runner(&delegate, instance.isolate());
-
-    {
-      gin::Runner::Scope scope(&runner);
-      runner.GetContextHolder()
-          ->isolate()
-          ->SetCaptureStackTraceForUncaughtExceptions(true);
-    }
-
-    base::CommandLine::StringVector args =
-        base::CommandLine::ForCurrentProcess()->GetArgs();
-    for (base::CommandLine::StringVector::const_iterator it = args.begin();
-         it != args.end(); ++it) {
-      base::ThreadTaskRunnerHandle::Get()->PostTask(
-          FROM_HERE,
-          base::Bind(gin::Run, runner.GetWeakPtr(), base::FilePath(*it)));
-    }
-
-    base::RunLoop().RunUntilIdle();
+    gin::Runner::Scope scope(&runner);
+    runner.GetContextHolder()
+        ->isolate()
+        ->SetCaptureStackTraceForUncaughtExceptions(true);
   }
 
-  // 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();
+  base::CommandLine::StringVector args =
+      base::CommandLine::ForCurrentProcess()->GetArgs();
+  for (base::CommandLine::StringVector::const_iterator it = args.begin();
+       it != args.end(); ++it) {
+    base::ThreadTaskRunnerHandle::Get()->PostTask(
+        FROM_HERE,
+        base::Bind(gin::Run, runner.GetWeakPtr(), base::FilePath(*it)));
+  }
 
+  base::RunLoop().RunUntilIdle();
   return 0;
 }