Introduce a SchedulerHelper in content/child/scheduler

content/renderer/scheduler/webthread_impl_for_scheduler_unittest.cc

Index: content/renderer/scheduler/webthread_impl_for_scheduler_unittest.cc
diff --git a/content/renderer/scheduler/webthread_impl_for_scheduler_unittest.cc b/content/renderer/scheduler/webthread_impl_for_scheduler_unittest.cc
index f943d33008f46d9b0dfb545bcc80a072d6cfe175..e9e359a3565c2196aed7095b7791db01bbc39e06 100644
--- a/content/renderer/scheduler/webthread_impl_for_scheduler_unittest.cc
+++ b/content/renderer/scheduler/webthread_impl_for_scheduler_unittest.cc
@@ -5,8 +5,8 @@
 #include "content/renderer/scheduler/webthread_impl_for_scheduler.h"
 
 #include "base/run_loop.h"
+#include "content/child/scheduler/scheduler_message_loop_delegate.h"
 #include "content/renderer/scheduler/renderer_scheduler_impl.h"
-#include "content/renderer/scheduler/renderer_scheduler_message_loop_delegate.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/WebKit/public/platform/WebTraceLocation.h"
@@ -31,13 +31,16 @@ class MockTaskObserver : public blink::WebThread::TaskObserver {
 class WebThreadImplForSchedulerTest : public testing::Test {
  public:
   WebThreadImplForSchedulerTest()
-      : scheduler_(
-            RendererSchedulerMessageLoopDelegate::Create(&message_loop_)),
+      : scheduler_(SchedulerMessageLoopDelegate::Create(&message_loop_)),
         default_task_runner_(scheduler_.DefaultTaskRunner()),
         thread_(&scheduler_) {}
 
   ~WebThreadImplForSchedulerTest() override {}
 
+  void SetWorkBatchSizeForTesting(size_t work_batch_size) {
+    scheduler_.SetWorkBatchSizeForTesting(work_batch_size);
+  }
+
  protected:
   void EatDefaultTask(MockTaskObserver* observer) {
     // The scheduler posts one extra DoWork() task automatically.