Replace gflags usages with rtc_base/flags in all targets based on test_main

webrtc/modules/audio_coding/neteq/tools/neteq_performance_test.cc

Index: webrtc/modules/audio_coding/neteq/tools/neteq_performance_test.cc
diff --git a/webrtc/modules/audio_coding/neteq/tools/neteq_performance_test.cc b/webrtc/modules/audio_coding/neteq/tools/neteq_performance_test.cc
index ef0e31e2f6a0ded47c0aa494becebb5a6f5ea714..8d0cf90d178e6ae2347eb202522a9cf6b1e4cfd7 100644
--- a/webrtc/modules/audio_coding/neteq/tools/neteq_performance_test.cc
+++ b/webrtc/modules/audio_coding/neteq/tools/neteq_performance_test.cc
@@ -80,7 +80,7 @@ int64_t NetEqPerformanceTest::Run(int runtime_ms,
   AudioFrame out_frame;
   while (time_now_ms < runtime_ms) {
     while (packet_input_time_ms <= time_now_ms) {
-      // Drop every N packets, where N = FLAGS_lossrate.
+      // Drop every N packets, where N = FLAG_lossrate.
       bool lost = false;
       if (lossrate > 0) {
         lost = ((rtp_header.sequenceNumber - 1) % lossrate) == 0;