MSE: Remove extraneous end_of_stream() check

SourceBufferStream should not be buffering EOS buffers internally. In
fact, any access of such a buffer's timestamp() method would DCHECK.
This change removes an extraneous condition for such buffers leftover
from long-removed cross-fade splicing code.

BUG=718641

Cq-Include-Trybots: master.tryserver.chromium.android:android_optional_gpu_tests_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel
Change-Id: Ie9a7bd9fb50195dd9f868462aae0879f5dedb6bc
Reviewed-on: https://chromium-review.googlesource.com/679734
Reviewed-by: Chrome Cunningham <chcunningham@chromium.org>
Commit-Queue: Matthew Wolenetz <wolenetz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#504201}
2 files changed