message: Remove anonymous namespace around ABSL_FLAG.
  TBR=tommi@webrtc.org
  No-Try: True
  Cr-Commit-Position: refs/heads/master@{#28607}
diff: #include "modules/audio_coding/neteq/tools/neteq_test_factory.h"
  #include "rtc_base/checks.h"
  -namespace {
  -
  ABSL_FLAG(std::string,
  replacement_audio_file,
  "",
  @@ -31,8 +29,6 @@ ABSL_FLAG(int,
  50,
  "Maximum allowed number of packets in the buffer");
  -} // namespace
  -
  namespace webrtc {
  namespace test {
  