SamplePdfFileViewer: delete dead code

Change-Id: I4ba5f22e4370665699546c82f0948a14f9396526
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/225543
Reviewed-by: Hal Canary <halcanary@google.com>
Commit-Queue: Hal Canary <halcanary@google.com>
2 files changed