Move over to ABSL logging and flags.

Removes gperftools too since that wants gflags.

Here come the fireworks.

Change-Id: I79cb7bcf60f1047fbfa28bfffc21a0fd692e4b1c
Signed-off-by: Austin Schuh <austin.linux@gmail.com>
diff --git a/y2023/localizer/localizer_main.cc b/y2023/localizer/localizer_main.cc
index 98f0e81..40b3ee5 100644
--- a/y2023/localizer/localizer_main.cc
+++ b/y2023/localizer/localizer_main.cc
@@ -1,16 +1,19 @@
+#include "absl/flags/flag.h"
+
 #include "aos/events/shm_event_loop.h"
 #include "aos/init.h"
 #include "frc971/constants/constants_sender_lib.h"
 #include "y2023/control_loops/drivetrain/drivetrain_base.h"
 #include "y2023/localizer/localizer.h"
 
-DEFINE_string(config, "aos_config.json", "Path to the config file to use.");
+ABSL_FLAG(std::string, config, "aos_config.json",
+          "Path to the config file to use.");
 
 int main(int argc, char *argv[]) {
   aos::InitGoogle(&argc, &argv);
 
   aos::FlatbufferDetachedBuffer<aos::Configuration> config =
-      aos::configuration::ReadConfig(FLAGS_config);
+      aos::configuration::ReadConfig(absl::GetFlag(FLAGS_config));
 
   frc971::constants::WaitForConstants<y2023::Constants>(&config.message());