bind: skip benchmarks in short mode

The bind benchmarks are implemented as Go tests, but take quite a
while to run. Skip them in short mode.

Change-Id: I49ede84863b047aa8307bc0ef752fc7aa21e2d65
Reviewed-on: https://go-review.googlesource.com/31637
Reviewed-by: David Crawshaw <crawshaw@golang.org>

bind/java/seq_test.go

@@ -52,6 +52,9 @@ func TestJavaSeqTest(t *testing.T) {
 //
 // while running the benchmark to see the results.
 func TestJavaSeqBench(t *testing.T) {
+	if testing.Short() {
+		t.Skip("skipping benchmark in short mode.")
+	}
 	runTest(t, []string{"golang.org/x/mobile/bind/benchmark"}, "", "SeqBench")
 }