Update from https://crrev.com/316786

base/process/process_info_win.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 "base/process/process_info.h"
 
 #include <windows.h>
 
 #include "base/basictypes.h"
+#include "base/memory/scoped_ptr.h"
 #include "base/time/time.h"
+#include "base/win/scoped_handle.h"
+#include "base/win/windows_version.h"
 
 namespace base {
 
-//static
+// static
 const Time CurrentProcessInfo::CreationTime() {
   FILETIME creation_time = {};
   FILETIME ignore = {};
   if (::GetProcessTimes(::GetCurrentProcess(), &creation_time, &ignore,
       &ignore, &ignore) == false)
     return Time();
 
   return Time::FromFileTime(creation_time);
 }
 
+IntegrityLevel GetCurrentProcessIntegrityLevel() {
+  if (win::GetVersion() < base::win::VERSION_VISTA)
+    return INTEGRITY_UNKNOWN;
+
+  HANDLE process_token;
+  if (!::OpenProcessToken(::GetCurrentProcess(),
+                          TOKEN_QUERY | TOKEN_QUERY_SOURCE, &process_token)) {
+    return INTEGRITY_UNKNOWN;
+  }
+  win::ScopedHandle scoped_process_token(process_token);
+
+  DWORD token_info_length = 0;
+  if (::GetTokenInformation(process_token, TokenIntegrityLevel, NULL, 0,
+                            &token_info_length) ||
+      ::GetLastError() != ERROR_INSUFFICIENT_BUFFER) {
+    return INTEGRITY_UNKNOWN;
+  }
+
+  scoped_ptr<char[]> token_label_bytes(new char[token_info_length]);
+  if (!token_label_bytes.get())
+    return INTEGRITY_UNKNOWN;
+
+  TOKEN_MANDATORY_LABEL* token_label =
+      reinterpret_cast<TOKEN_MANDATORY_LABEL*>(token_label_bytes.get());
+  if (!token_label)
+    return INTEGRITY_UNKNOWN;
+
+  if (!::GetTokenInformation(process_token, TokenIntegrityLevel, token_label,
+                             token_info_length, &token_info_length)) {
+    return INTEGRITY_UNKNOWN;
+  }
+
+  DWORD integrity_level = *::GetSidSubAuthority(
+      token_label->Label.Sid,
+      static_cast<DWORD>(*::GetSidSubAuthorityCount(token_label->Label.Sid)-1));
+
+  if (integrity_level < SECURITY_MANDATORY_MEDIUM_RID)
+    return LOW_INTEGRITY;
+
+  if (integrity_level >= SECURITY_MANDATORY_MEDIUM_RID &&
+      integrity_level < SECURITY_MANDATORY_HIGH_RID) {
+    return MEDIUM_INTEGRITY;
+  }
+
+  if (integrity_level >= SECURITY_MANDATORY_HIGH_RID)
+    return HIGH_INTEGRITY;
+
+  NOTREACHED();
+  return INTEGRITY_UNKNOWN;
+}
+
 }  // namespace base