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/frc971/constants/constants_sender_example.cc b/frc971/constants/constants_sender_example.cc
index a0b23ce..2beb9ec 100644
--- a/frc971/constants/constants_sender_example.cc
+++ b/frc971/constants/constants_sender_example.cc
@@ -1,5 +1,6 @@
-#include "gflags/gflags.h"
-#include "glog/logging.h"
+#include "absl/flags/flag.h"
+#include "absl/log/check.h"
+#include "absl/log/log.h"
 
 #include "aos/configuration.h"
 #include "aos/events/shm_event_loop.h"
@@ -9,19 +10,20 @@
 #include "frc971/constants/testdata/constants_data_generated.h"
 #include "frc971/constants/testdata/constants_list_generated.h"
 
-DEFINE_string(config, "frc971/constants/testdata/aos_config.json",
-              "Path to the config.");
-DEFINE_string(constants_path, "frc971/constants/testdata/test_constants.json",
-              "Path to the constant file");
+ABSL_FLAG(std::string, config, "frc971/constants/testdata/aos_config.json",
+          "Path to the config.");
+ABSL_FLAG(std::string, constants_path,
+          "frc971/constants/testdata/test_constants.json",
+          "Path to the constant file");
 // This is just a sample binary
 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));
   aos::ShmEventLoop event_loop(&config.message());
   frc971::constants::ConstantSender<frc971::constants::testdata::ConstantsData,
                                     frc971::constants::testdata::ConstantsList>
-      constants_sender(&event_loop, FLAGS_constants_path);
+      constants_sender(&event_loop, absl::GetFlag(FLAGS_constants_path));
   event_loop.Run();
 
   return 0;