Update {virtual,override} to follow C++11 style in content.

content/common/sandbox_mac_system_access_unittest.mm

 // 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.
 
 #import <Cocoa/Cocoa.h>
 
 #include "base/files/file_util.h"
 #include "base/files/scoped_file.h"
 #include "base/logging.h"
 #include "base/strings/sys_string_conversions.h"
@@ skipping 138 matching lines @@
 TEST_F(MacSandboxTest, OpenSSLAccess) {
   EXPECT_TRUE(RunTestInAllSandboxTypes("MacSandboxedOpenSSLTestCase", NULL));
 }
 
 #else  // !defined(USE_OPENSSL)
 
 //--------------------- NSS Sandboxing ----------------------
 // Test case for checking sandboxing of NSS initialization.
 class MacSandboxedNSSTestCase : public MacSandboxTestCase {
  public:
-  virtual bool SandboxedTest() override;
+  bool SandboxedTest() override;
 };
 
 REGISTER_SANDBOX_TEST_CASE(MacSandboxedNSSTestCase);
 
 bool MacSandboxedNSSTestCase::SandboxedTest() {
   // If NSS cannot read from /dev/urandom, NSS initialization will call abort(),
   // which will cause this test case to fail.
   crypto::ForceNSSNoDBInit();
   crypto::EnsureNSSInit();
   return true;
 }
 
 TEST_F(MacSandboxTest, NSSAccess) {
   EXPECT_TRUE(RunTestInAllSandboxTypes("MacSandboxedNSSTestCase", NULL));
 }
 
 #endif  // defined(USE_OPENSSL)
 
 }  // namespace content