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

webrtc/modules/audio_coding/neteq/tools/neteq_quality_test.h

Index: webrtc/modules/audio_coding/neteq/tools/neteq_quality_test.h
diff --git a/webrtc/modules/audio_coding/neteq/tools/neteq_quality_test.h b/webrtc/modules/audio_coding/neteq/tools/neteq_quality_test.h
index 731a7c922985ef8b1d5a88df8056f49490269dee..c1964b6dc867898797e35cc804b4c576aa13d52d 100644
--- a/webrtc/modules/audio_coding/neteq/tools/neteq_quality_test.h
+++ b/webrtc/modules/audio_coding/neteq/tools/neteq_quality_test.h
@@ -13,7 +13,6 @@
 
 #include <fstream>
 #include <memory>
-#include <gflags/gflags.h>
 
 #include "webrtc/common_types.h"
 #include "webrtc/modules/audio_coding/neteq/include/neteq.h"
@@ -21,11 +20,10 @@
 #include "webrtc/modules/audio_coding/neteq/tools/input_audio_file.h"
 #include "webrtc/modules/audio_coding/neteq/tools/rtp_generator.h"
 #include "webrtc/modules/include/module_common_types.h"
+#include "webrtc/rtc_base/flags.h"
 #include "webrtc/test/gtest.h"
 #include "webrtc/typedefs.h"
 
-using google::RegisterFlagValidator;
-
 namespace webrtc {
 namespace test {