Use timer task runner for V8PerIsolate tasks

gin/test/file_runner.cc

 // Copyright 2013 The Chromium 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 "gin/test/file_runner.h"
 
 #include "base/files/file_util.h"
 #include "base/message_loop/message_loop.h"
 #include "base/path_service.h"
 #include "base/run_loop.h"
+#include "base/threading/thread_task_runner_handle.h"
 #include "gin/array_buffer.h"
 #include "gin/converter.h"
 #include "gin/modules/console.h"
 #include "gin/modules/module_registry.h"
 #include "gin/public/context_holder.h"
 #include "gin/public/isolate_holder.h"
 #include "gin/test/file.h"
 #include "gin/test/gc.h"
 #include "gin/test/gtest.h"
 #include "gin/try_catch.h"
@@ skipping 41 matching lines @@
 
 #ifdef V8_USE_EXTERNAL_STARTUP_DATA
   gin::V8Initializer::LoadV8Snapshot();
   gin::V8Initializer::LoadV8Natives();
 #endif
 
   gin::IsolateHolder::Initialize(gin::IsolateHolder::kStrictMode,
                                  gin::IsolateHolder::kStableV8Extras,
                                  gin::ArrayBufferAllocator::SharedInstance());
 
-  gin::IsolateHolder instance;
+  gin::IsolateHolder instance(base::ThreadTaskRunnerHandle::Get());
   gin::ShellRunner runner(delegate, instance.isolate());
   {
     gin::Runner::Scope scope(&runner);
     instance.isolate()->SetCaptureStackTraceForUncaughtExceptions(true);
     runner.Run(source, path.AsUTF8Unsafe());
 
     if (run_until_idle) {
       base::RunLoop().RunUntilIdle();
     } else {
       base::RunLoop().Run();
     }
 
     v8::Local<v8::Value> result = runner.global()->Get(
         StringToSymbol(runner.GetContextHolder()->isolate(), "result"));
     EXPECT_EQ("PASS", V8ToString(result));
   }
 }
 
 }  // namespace gin