Use TaskScheduler instead of WorkerPool in v8_platform.cc.

extensions/renderer/api_binding_test.h

Index: extensions/renderer/api_binding_test.h
diff --git a/extensions/renderer/api_binding_test.h b/extensions/renderer/api_binding_test.h
index d72de47eb12e3812c90e6879a0d4895bd3e1353f..4a67989ec394ce0a32e4e4108c2567c058ce2bf8 100644
--- a/extensions/renderer/api_binding_test.h
+++ b/extensions/renderer/api_binding_test.h
@@ -9,6 +9,7 @@
 
 #include "base/macros.h"
 #include "base/message_loop/message_loop.h"
+#include "base/test/scoped_async_task_scheduler.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "v8/include/v8.h"
 
@@ -43,6 +44,11 @@ class APIBindingTest : public testing::Test {
 
  private:
   base::MessageLoop message_loop_;
+
+  // Required by gin::V8Platform::CallOnBackgroundThread(). Can't be a
+  // ScopedTaskScheduler because v8 synchronously waits for tasks to run.
+  base::test::ScopedAsyncTaskScheduler scoped_async_task_scheduler_;
+
   std::unique_ptr<gin::IsolateHolder> isolate_holder_;
   std::unique_ptr<gin::ContextHolder> context_holder_;