scheduler: Add an unthrottled per-frame task runner

content/test/fake_renderer_scheduler.h

Index: content/test/fake_renderer_scheduler.h
diff --git a/content/test/fake_renderer_scheduler.h b/content/test/fake_renderer_scheduler.h
index 2a5b621b4827a5bb1880b637ed0735d1bfde9e8a..5de64e46b22706b4dacbe5442a3165b2839a56bf 100644
--- a/content/test/fake_renderer_scheduler.h
+++ b/content/test/fake_renderer_scheduler.h
@@ -27,6 +27,8 @@ class FakeRendererScheduler : public scheduler::RendererScheduler {
       const char* name) override;
   scoped_refptr<scheduler::TaskQueue> NewTimerTaskRunner(
       const char* name) override;
+  scoped_refptr<scheduler::TaskQueue> NewUnthrottledTaskRunner(
+      const char* name) override;
   std::unique_ptr<scheduler::RenderWidgetSchedulingState>
   NewRenderWidgetSchedulingState() override;
   void WillBeginFrame(const cc::BeginFrameArgs& args) override;