Update from https://crrev.com/311076

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 <fcntl.h>
 #include <stdio.h>
 #include <sys/stat.h>
@@ skipping 30 matching lines @@
   struct stat parrent;
   CHECK_EQ(0, stat("..", &parrent));
   CHECK_EQ(current.st_dev, parrent.st_dev);
   CHECK_EQ(current.st_ino, parrent.st_ino);
   CHECK_EQ(current.st_mode, parrent.st_mode);
   CHECK_EQ(current.st_uid, parrent.st_uid);
   CHECK_EQ(current.st_gid, parrent.st_gid);
   return true;
 }
 
-// Give dynamic tools a simple thing to test.
-TEST(Credentials, CreateAndDestroy) {
-  {
-    Credentials cred1;
-    (void) cred1;
-  }
-  scoped_ptr<Credentials> cred2(new Credentials);
-}
-
 SANDBOX_TEST(Credentials, DropAllCaps) {
-  Credentials creds;
-  CHECK(creds.DropAllCapabilities());
-  CHECK(!creds.HasAnyCapability());
+  CHECK(Credentials::DropAllCapabilities());
+  CHECK(!Credentials::HasAnyCapability());
 }
 
 SANDBOX_TEST(Credentials, GetCurrentCapString) {
-  Credentials creds;
-  CHECK(creds.DropAllCapabilities());
+  CHECK(Credentials::DropAllCapabilities());
   const char kNoCapabilityText[] = "=";
-  CHECK(*creds.GetCurrentCapString() == kNoCapabilityText);
+  CHECK(*Credentials::GetCurrentCapString() == kNoCapabilityText);
 }
 
 SANDBOX_TEST(Credentials, MoveToNewUserNS) {
-  Credentials creds;
-  CHECK(creds.DropAllCapabilities());
-  bool moved_to_new_ns = creds.MoveToNewUserNS();
+  CHECK(Credentials::DropAllCapabilities());
+  bool moved_to_new_ns = Credentials::MoveToNewUserNS();
   fprintf(stdout,
           "Unprivileged CLONE_NEWUSER supported: %s\n",
           moved_to_new_ns ? "true." : "false.");
   fflush(stdout);
   if (!moved_to_new_ns) {
     fprintf(stdout, "This kernel does not support unprivileged namespaces. "
             "USERNS tests will succeed without running.\n");
     fflush(stdout);
     return;
   }
-  CHECK(creds.HasAnyCapability());
-  CHECK(creds.DropAllCapabilities());
-  CHECK(!creds.HasAnyCapability());
+  CHECK(Credentials::HasAnyCapability());
+  CHECK(Credentials::DropAllCapabilities());
+  CHECK(!Credentials::HasAnyCapability());
 }
 
 SANDBOX_TEST(Credentials, SupportsUserNS) {
-  Credentials creds;
-  CHECK(creds.DropAllCapabilities());
+  CHECK(Credentials::DropAllCapabilities());
   bool user_ns_supported = Credentials::SupportsNewUserNS();
-  bool moved_to_new_ns = creds.MoveToNewUserNS();
+  bool moved_to_new_ns = Credentials::MoveToNewUserNS();
   CHECK_EQ(user_ns_supported, moved_to_new_ns);
 }
 
 SANDBOX_TEST(Credentials, UidIsPreserved) {
-  Credentials creds;
-  CHECK(creds.DropAllCapabilities());
+  CHECK(Credentials::DropAllCapabilities());
   uid_t old_ruid, old_euid, old_suid;
   gid_t old_rgid, old_egid, old_sgid;
   PCHECK(0 == getresuid(&old_ruid, &old_euid, &old_suid));
   PCHECK(0 == getresgid(&old_rgid, &old_egid, &old_sgid));
   // Probably missing kernel support.
-  if (!creds.MoveToNewUserNS()) return;
+  if (!Credentials::MoveToNewUserNS()) return;
   uid_t new_ruid, new_euid, new_suid;
   PCHECK(0 == getresuid(&new_ruid, &new_euid, &new_suid));
   CHECK(old_ruid == new_ruid);
   CHECK(old_euid == new_euid);
   CHECK(old_suid == new_suid);
 
   gid_t new_rgid, new_egid, new_sgid;
   PCHECK(0 == getresgid(&new_rgid, &new_egid, &new_sgid));
   CHECK(old_rgid == new_rgid);
   CHECK(old_egid == new_egid);
   CHECK(old_sgid == new_sgid);
 }
 
-bool NewUserNSCycle(Credentials* creds) {
-  DCHECK(creds);
-  if (!creds->MoveToNewUserNS() ||
-      !creds->HasAnyCapability() ||
-      !creds->DropAllCapabilities() ||
-      creds->HasAnyCapability()) {
+bool NewUserNSCycle() {
+  if (!Credentials::MoveToNewUserNS() ||
+      !Credentials::HasAnyCapability() ||
+      !Credentials::DropAllCapabilities() ||
+      Credentials::HasAnyCapability()) {
     return false;
   }
   return true;
 }
 
 SANDBOX_TEST(Credentials, NestedUserNS) {
-  Credentials creds;
-  CHECK(creds.DropAllCapabilities());
+  CHECK(Credentials::DropAllCapabilities());
   // Probably missing kernel support.
-  if (!creds.MoveToNewUserNS()) return;
-  CHECK(creds.DropAllCapabilities());
+  if (!Credentials::MoveToNewUserNS()) return;
+  CHECK(Credentials::DropAllCapabilities());
   // As of 3.12, the kernel has a limit of 32. See create_user_ns().
   const int kNestLevel = 10;
   for (int i = 0; i < kNestLevel; ++i) {
-    CHECK(NewUserNSCycle(&creds)) << "Creating new user NS failed at iteration "
+    CHECK(NewUserNSCycle()) << "Creating new user NS failed at iteration "
                                   << i << ".";
   }
 }
 
 // Test the WorkingDirectoryIsRoot() helper.
 TEST(Credentials, CanDetectRoot) {
   ASSERT_EQ(0, chdir("/proc/"));
   ASSERT_FALSE(WorkingDirectoryIsRoot());
   ASSERT_EQ(0, chdir("/"));
   ASSERT_TRUE(WorkingDirectoryIsRoot());
 }
 
 SANDBOX_TEST(Credentials, DISABLE_ON_LSAN(DropFileSystemAccessIsSafe)) {
-  Credentials creds;
-  CHECK(creds.DropAllCapabilities());
+  CHECK(Credentials::DropAllCapabilities());
   // Probably missing kernel support.
-  if (!creds.MoveToNewUserNS()) return;
-  CHECK(creds.DropFileSystemAccess());
+  if (!Credentials::MoveToNewUserNS()) return;
+  CHECK(Credentials::DropFileSystemAccess());
   CHECK(!DirectoryExists("/proc"));
   CHECK(WorkingDirectoryIsRoot());
   // We want the chroot to never have a subdirectory. A subdirectory
   // could allow a chroot escape.
   CHECK_NE(0, mkdir("/test", 0700));
 }
 
 // Check that after dropping filesystem access and dropping privileges
 // it is not possible to regain capabilities.
 SANDBOX_TEST(Credentials, DISABLE_ON_LSAN(CannotRegainPrivileges)) {
-  Credentials creds;
-  CHECK(creds.DropAllCapabilities());
+  CHECK(Credentials::DropAllCapabilities());
   // Probably missing kernel support.
-  if (!creds.MoveToNewUserNS()) return;
-  CHECK(creds.DropFileSystemAccess());
-  CHECK(creds.DropAllCapabilities());
+  if (!Credentials::MoveToNewUserNS()) return;
+  CHECK(Credentials::DropFileSystemAccess());
+  CHECK(Credentials::DropAllCapabilities());
 
   // The kernel should now prevent us from regaining capabilities because we
   // are in a chroot.
   CHECK(!Credentials::SupportsNewUserNS());
-  CHECK(!creds.MoveToNewUserNS());
+  CHECK(!Credentials::MoveToNewUserNS());
 }
 
 }  // namespace.
 
 }  // namespace sandbox.