oauth2: drop pre-1.4 workaround

Change-Id: Icac33569b4937602b0aac46ec36cc85b5aa53877
Reviewed-on: https://go-review.googlesource.com/6071
Reviewed-by: Andrew Gerrand <adg@golang.org>

google/example_test.go

@@ -11,7 +11,6 @@ import (
 	"io/ioutil"
 	"log"
 	"net/http"
-	"testing"
 
 	"golang.org/x/oauth2"
 	"golang.org/x/oauth2/google"
@@ -20,10 +19,6 @@ import (
 	"google.golang.org/appengine/urlfetch"
 )
 
-// Remove after Go 1.4.
-// Related to https://codereview.appspot.com/107320046
-func TestA(t *testing.T) {}
-
 func Example_webServer() {
 	// Your credentials should be obtained from the Google
 	// Developer Console (https://console.developers.google.com).