Delete the non-const version of the EncodedImage::data() method.

Bug: webrtc:9378
Change-Id: I84ace3ca6a2eb4d0f7c3d4e62f815d77df581bfa
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/185122
Reviewed-by: Artem Titov <titovartem@webrtc.org>
Reviewed-by: Philip Eliasson <philipel@webrtc.org>
Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#32197}
diff --git a/modules/video_coding/frame_buffer.cc b/modules/video_coding/frame_buffer.cc
index d30170a..09c2733 100644
--- a/modules/video_coding/frame_buffer.cc
+++ b/modules/video_coding/frame_buffer.cc
@@ -134,7 +134,9 @@
   if (packet.sizeBytes > 0)
     CopyCodecSpecific(&packet.video_header);
 
-  int retVal = _sessionInfo.InsertPacket(packet, data(), frame_data);
+  int retVal = _sessionInfo.InsertPacket(
+      packet, encoded_image_buffer_ ? encoded_image_buffer_->data() : nullptr,
+      frame_data);
   if (retVal == -1) {
     return kSizeError;
   } else if (retVal == -2) {