Use auto, not const auto*, for libyuv function pointers

content/renderer/media/webrtc/video_destination_handler.cc

Index: content/renderer/media/webrtc/video_destination_handler.cc
diff --git a/content/renderer/media/webrtc/video_destination_handler.cc b/content/renderer/media/webrtc/video_destination_handler.cc
index 46384e8bb3b00ff4ef8f846ca7697e287990c2a7..d2dfb8f1e80978c7c2da303e6ebabb2a9482db75 100644
--- a/content/renderer/media/webrtc/video_destination_handler.cc
+++ b/content/renderer/media/webrtc/video_destination_handler.cc
@@ -188,7 +188,7 @@ void PpFrameWriter::FrameWriterDelegate::DeliverFrameOnIO(
   // libyuv specifies fourcc/channel ordering the same as webrtc. That is why
   // the naming is reversed compared to PixelEndian and PP_ImageDataFormat which
   // describes the memory layout from the lowest address to the highest.
-  const auto* xxxxToI420 =
+  auto xxxxToI420 =
       (endian_ == AXXX) ? &libyuv::BGRAToI420 : &libyuv::ARGBToI420;
   xxxxToI420(data,
              stride,