Update from https://crrev.com/318214

sandbox/linux/services/namespace_sandbox_unittest.cc

 // Copyright 2015 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/namespace_sandbox.h"
 
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <unistd.h>
 
 #include <string>
 #include <utility>
 
 #include "base/command_line.h"
 #include "base/files/file_enumerator.h"
 #include "base/files/file_path.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/process/launch.h"
 #include "base/process/process.h"
 #include "base/test/multiprocess_test.h"
 #include "sandbox/linux/services/credentials.h"
 #include "sandbox/linux/services/namespace_utils.h"
+#include "sandbox/linux/services/proc_util.h"
 #include "sandbox/linux/tests/unit_tests.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "testing/multiprocess_func_list.h"
 
 namespace sandbox {
 
 namespace {
 
 bool RootDirectoryIsEmpty() {
   base::FilePath root("/");
@@ skipping 44 matching lines @@
   return 0;
 }
 
 TEST_F(NamespaceSandboxTest, BasicUsage) {
   TestProc("SimpleChildProcess");
 }
 
 MULTIPROCESS_TEST_MAIN(ChrootMe) {
   CHECK(!RootDirectoryIsEmpty());
   CHECK(sandbox::Credentials::MoveToNewUserNS());
-  CHECK(sandbox::Credentials::DropFileSystemAccess());
+  CHECK(sandbox::Credentials::DropFileSystemAccess(ProcUtil::OpenProc().get()));
   CHECK(RootDirectoryIsEmpty());
   return 0;
 }
 
 // Temporarily disabled on ASAN due to crbug.com/451603.
 TEST_F(NamespaceSandboxTest, DISABLE_ON_ASAN(ChrootAndDropCapabilities)) {
   TestProc("ChrootMe");
 }
 
 MULTIPROCESS_TEST_MAIN(NestedNamespaceSandbox) {
@@ skipping 14 matching lines @@
   return 0;
 }
 
 TEST_F(NamespaceSandboxTest, NestedNamespaceSandbox) {
   TestProc("NestedNamespaceSandbox");
 }
 
 }  // namespace
 
 }  // namespace sandbox