Check the length of marker before reading it

Bug: os-fuzz:6295
Change-Id: I0ea9a3c54d61d41f21f2e9b945ab83fa2beb00d8
Reviewed-on: https://skia-review.googlesource.com/107025
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Leon Scroggins <scroggo@google.com>
1 file changed