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/y2019/vision/debug_viewer.cc b/y2019/vision/debug_viewer.cc
index 1a93f87..31fee54 100644
--- a/y2019/vision/debug_viewer.cc
+++ b/y2019/vision/debug_viewer.cc
@@ -1,6 +1,6 @@
 #include <iostream>
 
-#include "gflags/gflags.h"
+#include "absl/flags/flag.h"
 #include <Eigen/Dense>
 
 #include "aos/vision/blob/move_scale.h"
@@ -19,7 +19,7 @@
 using aos::vision::Segment;
 using aos::vision::Vector;
 
-DEFINE_int32(camera, 10, "The camera to use the intrinsics for");
+ABSL_FLAG(int32_t, camera, 10, "The camera to use the intrinsics for");
 
 namespace y2019::vision {