binderRpcBenchmark: set label

label is clearer to interpret output than looking
up numbers, and this doesn't break JSON parsing
of the output.

Bug: 271994750
Test: binderRpcBenchmark
Change-Id: Idf38145fbd6c321be34379d4b5589b9cab4ed81c
diff --git a/libs/binder/tests/binderRpcBenchmark.cpp b/libs/binder/tests/binderRpcBenchmark.cpp
index 5939273..9c96c41 100644
--- a/libs/binder/tests/binderRpcBenchmark.cpp
+++ b/libs/binder/tests/binderRpcBenchmark.cpp
@@ -129,12 +129,33 @@
     }
 }
 
+static void SetLabel(benchmark::State& state) {
+    Transport transport = static_cast<Transport>(state.range(0));
+    switch (transport) {
+#ifdef __BIONIC__
+        case KERNEL:
+            state.SetLabel("kernel");
+            break;
+#endif
+        case RPC:
+            state.SetLabel("rpc");
+            break;
+        case RPC_TLS:
+            state.SetLabel("rpc_tls");
+            break;
+        default:
+            LOG(FATAL) << "Unknown transport value: " << transport;
+    }
+}
+
 void BM_pingTransaction(benchmark::State& state) {
     sp<IBinder> binder = getBinderForOptions(state);
 
     while (state.KeepRunning()) {
         CHECK_EQ(OK, binder->pingBinder());
     }
+
+    SetLabel(state);
 }
 BENCHMARK(BM_pingTransaction)->ArgsProduct({kTransportList});
 
@@ -164,6 +185,8 @@
         Status ret = iface->repeatString(str, &out);
         CHECK(ret.isOk()) << ret;
     }
+
+    SetLabel(state);
 }
 BENCHMARK(BM_repeatTwoPageString)->ArgsProduct({kTransportList});
 
@@ -182,6 +205,8 @@
         Status ret = iface->repeatBytes(bytes, &out);
         CHECK(ret.isOk()) << ret;
     }
+
+    SetLabel(state);
 }
 BENCHMARK(BM_throughputForTransportAndBytes)
         ->ArgsProduct({kTransportList,
@@ -201,6 +226,8 @@
         Status ret = iface->repeatBinder(binder, &out);
         CHECK(ret.isOk()) << ret;
     }
+
+    SetLabel(state);
 }
 BENCHMARK(BM_repeatBinder)->ArgsProduct({kTransportList});
 
@@ -228,11 +255,6 @@
     ::benchmark::Initialize(&argc, argv);
     if (::benchmark::ReportUnrecognizedArguments(argc, argv)) return 1;
 
-    std::cerr << "Tests suffixes:" << std::endl;
-    std::cerr << "\t.../" << Transport::KERNEL << " is KERNEL" << std::endl;
-    std::cerr << "\t.../" << Transport::RPC << " is RPC" << std::endl;
-    std::cerr << "\t.../" << Transport::RPC_TLS << " is RPC with TLS" << std::endl;
-
 #ifdef __BIONIC__
     if (0 == fork()) {
         prctl(PR_SET_PDEATHSIG, SIGHUP); // racey, okay