base: Introduce NullCallback
This helper makes it easier to pass in null callbacks by avoiding the
long callback names.
Also, base::NullCallback() would be more explicit that the callback is
null than FooCallback().
This CL only converts *Decoder::WaitingForDecryptionKeyCB() to use
base::NullCallback() as an example. More callbacks will be converted
later.
Bug: 842277
Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;luci.chromium.try:win_optional_gpu_tests_rel
Change-Id: I03bdf9d3ff6be30161b9e24118827377f5350d40
Reviewed-on: https://chromium-review.googlesource.com/1055854
Reviewed-by: Taiju Tsuiki <tzik@chromium.org>
Commit-Queue: Xiaohan Wang <xhwang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#558494}
CrOS-Libchrome-Original-Commit: 4f568e77d832f87600f679d17396e7cc4d464d05
1 file changed