veyron/runtimes/google/ipc/benchmark: change to use roaming profile

* Change to use static profile for benchmarks with other protocols like
  "ws" with --veyron.tcp.protocol=ws.
* Remove unnecessary testing principal setting since it's done in
  IitForTest().

Change-Id: Ifa6dc3a712ca35933a37fcabfbed72d0e31a835d
diff --git a/runtimes/google/ipc/benchmark/benchmark_test.go b/runtimes/google/ipc/benchmark/benchmark_test.go
index 7bd0db8..67e36c5 100644
--- a/runtimes/google/ipc/benchmark/benchmark_test.go
+++ b/runtimes/google/ipc/benchmark/benchmark_test.go
@@ -6,8 +6,7 @@
 
 	"v.io/core/veyron/lib/testutil"
 	"v.io/core/veyron/lib/testutil/benchmark"
-	tsecurity "v.io/core/veyron/lib/testutil/security"
-	_ "v.io/core/veyron/profiles"
+	_ "v.io/core/veyron/profiles/static"
 
 	"v.io/core/veyron2"
 	"v.io/core/veyron2/context"
@@ -107,12 +106,6 @@
 	var shutdown veyron2.Shutdown
 	ctx, shutdown = testutil.InitForTest()
 
-	var err error
-	ctx, err = veyron2.SetPrincipal(ctx, tsecurity.NewPrincipal("test-blessing"))
-	if err != nil {
-		panic(err)
-	}
-
 	var serverStop func()
 	serverAddr, serverStop = StartServer(ctx, veyron2.GetListenSpec(ctx))