Fix typo in rtc_base/thread_checker.h.

Bug: None
No-Try: True
Change-Id: Ie5562b3af54c2ce95d7433ba4237f976a2e60df3
Reviewed-on: https://webrtc-review.googlesource.com/c/119040
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Commit-Queue: Karl Wiberg <kwiberg@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#26361}
diff --git a/rtc_base/thread_checker.h b/rtc_base/thread_checker.h
index baff897..43f7320 100644
--- a/rtc_base/thread_checker.h
+++ b/rtc_base/thread_checker.h
@@ -152,12 +152,12 @@
 //     // Will fail at runtime when DCHECK is enabled:
 //     // encoder_->Encode();
 //     // Will work:
-//     rtc::scoped_ref_ptr<Encoder> encoder = encoder_;
+//     rtc::scoped_refptr<Encoder> encoder = encoder_;
 //     encoder_->Queue()->PostTask([encoder] { encoder->Encode(); });
 //   }
 //
 //  private:
-//   rtc::scoped_ref_ptr<Encoder> encoder_;
+//   rtc::scoped_refptr<Encoder> encoder_;
 // }
 
 // Document if a function expected to be called from same thread/task queue.