Linux sandbox: print kernel support in credentials unittests.

sandbox/linux/services/credentials_unittest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "sandbox/linux/services/credentials.h"
 
 #include <errno.h>
+#include <stdio.h>
 #include <unistd.h>
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "sandbox/linux/tests/unit_tests.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace sandbox {
 
 namespace {
@@ skipping 43 matching lines @@
   Credentials creds;
   CHECK(creds.DropAllCapabilities());
   const char kNoCapabilityText[] = "=";
   CHECK(*creds.GetCurrentCapString() == kNoCapabilityText);
 }
 
 SANDBOX_TEST(Credentials, MoveToNewUserNS) {
   Credentials creds;
   creds.DropAllCapabilities();
   bool userns_supported = creds.MoveToNewUserNS();
-  printf("Unprivileged CLONE_NEWUSER supported: %s\n",
-         userns_supported ? "true." : "false.");
+  fprintf(stdout, "Unprivileged CLONE_NEWUSER supported: %s\n",
+          userns_supported ? "true." : "false.");
+  fflush(stdout);
   if (!userns_supported) {
-    printf("This kernel does not support unprivileged namespaces. "
-           "USERNS tests will all pass.\n");
+    fprintf(stdout, "This kernel does not support unprivileged namespaces. "
+            "USERNS tests will succeed without running.\n");
+    fflush(stdout);
     return;
   }
   CHECK(creds.HasAnyCapability());
   creds.DropAllCapabilities();
   CHECK(!creds.HasAnyCapability());
 }
 
 SANDBOX_TEST(Credentials, UidIsPreserved) {
   Credentials creds;
   creds.DropAllCapabilities();
@@ skipping 73 matching lines @@
   CHECK(creds.DropAllCapabilities());
 
   // The kernel should now prevent us from regaining capabilities because we
   // are in a chroot.
   CHECK(!creds.MoveToNewUserNS());
 }
 
 }  // namespace.
 
 }  // namespace sandbox.