Adding upstream version 110.0.1.upstream/110.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

20 files changed, 3816 insertions, 0 deletions

diff --git a/security/sandbox/chromium/base/threading/platform_thread.cc b/security/sandbox/chromium/base/threading/platform_thread.cc
new file mode 100644
index 0000000000..ae0a4499e7
--- /dev/null
+++ b/security/sandbox/chromium/base/threading/platform_thread.cc
@@ -0,0 +1,51 @@
+// Copyright 2018 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/threading/platform_thread.h"
+
+#include <atomic>
+#include <memory>
+
+#include "base/feature_list.h"
+
+namespace base {
+
+namespace {
+
+// Whether thread priorities should be used. When disabled,
+// PlatformThread::SetCurrentThreadPriority() no-ops.
+const Feature kThreadPrioritiesFeature{"ThreadPriorities",
+                                       FEATURE_ENABLED_BY_DEFAULT};
+
+// Whether thread priorities should be used.
+//
+// PlatformThread::SetCurrentThreadPriority() doesn't query the state of the
+// feature directly because FeatureList initialization is not always
+// synchronized with PlatformThread::SetCurrentThreadPriority().
+std::atomic<bool> g_use_thread_priorities(true);
+
+}  // namespace
+
+// static
+void PlatformThread::SetCurrentThreadPriority(ThreadPriority priority) {
+  if (g_use_thread_priorities.load())
+    SetCurrentThreadPriorityImpl(priority);
+}
+
+namespace internal {
+
+void InitializeThreadPrioritiesFeature() {
+  // A DCHECK is triggered on FeatureList initialization if the state of a
+  // feature has been checked before. To avoid triggering this DCHECK in unit
+  // tests that call this before initializing the FeatureList, only check the
+  // state of the feature if the FeatureList is initialized.
+  if (FeatureList::GetInstance() &&
+      !FeatureList::IsEnabled(kThreadPrioritiesFeature)) {
+    g_use_thread_priorities.store(false);
+  }
+}
+
+}  // namespace internal
+
+}  // namespace base
diff --git a/security/sandbox/chromium/base/threading/platform_thread.h b/security/sandbox/chromium/base/threading/platform_thread.h
new file mode 100644
index 0000000000..aa5b9526c1
--- /dev/null
+++ b/security/sandbox/chromium/base/threading/platform_thread.h
@@ -0,0 +1,259 @@
+// 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.
+
+// WARNING: You should *NOT* be using this class directly.  PlatformThread is
+// the low-level platform-specific abstraction to the OS's threading interface.
+// You should instead be using a message-loop driven Thread, see thread.h.
+
+#ifndef BASE_THREADING_PLATFORM_THREAD_H_
+#define BASE_THREADING_PLATFORM_THREAD_H_
+
+#include <stddef.h>
+
+#include "base/base_export.h"
+#include "base/macros.h"
+#include "base/time/time.h"
+#include "build/build_config.h"
+
+#if defined(OS_WIN)
+#include "base/win/windows_types.h"
+#elif defined(OS_FUCHSIA)
+#include <zircon/types.h>
+#elif defined(OS_MACOSX)
+#include <mach/mach_types.h>
+#elif defined(OS_POSIX)
+#include <pthread.h>
+#include <unistd.h>
+#endif
+
+namespace base {
+
+// Used for logging. Always an integer value.
+#if defined(OS_WIN)
+typedef DWORD PlatformThreadId;
+#elif defined(OS_FUCHSIA)
+typedef zx_handle_t PlatformThreadId;
+#elif defined(OS_MACOSX)
+typedef mach_port_t PlatformThreadId;
+#elif defined(OS_POSIX)
+typedef pid_t PlatformThreadId;
+#endif
+
+// Used for thread checking and debugging.
+// Meant to be as fast as possible.
+// These are produced by PlatformThread::CurrentRef(), and used to later
+// check if we are on the same thread or not by using ==. These are safe
+// to copy between threads, but can't be copied to another process as they
+// have no meaning there. Also, the internal identifier can be re-used
+// after a thread dies, so a PlatformThreadRef cannot be reliably used
+// to distinguish a new thread from an old, dead thread.
+class PlatformThreadRef {
+ public:
+#if defined(OS_WIN)
+  typedef DWORD RefType;
+#else  //  OS_POSIX
+  typedef pthread_t RefType;
+#endif
+  constexpr PlatformThreadRef() : id_(0) {}
+
+  explicit constexpr PlatformThreadRef(RefType id) : id_(id) {}
+
+  bool operator==(PlatformThreadRef other) const {
+    return id_ == other.id_;
+  }
+
+  bool operator!=(PlatformThreadRef other) const { return id_ != other.id_; }
+
+  bool is_null() const {
+    return id_ == 0;
+  }
+ private:
+  RefType id_;
+};
+
+// Used to operate on threads.
+class PlatformThreadHandle {
+ public:
+#if defined(OS_WIN)
+  typedef void* Handle;
+#elif defined(OS_POSIX) || defined(OS_FUCHSIA)
+  typedef pthread_t Handle;
+#endif
+
+  constexpr PlatformThreadHandle() : handle_(0) {}
+
+  explicit constexpr PlatformThreadHandle(Handle handle) : handle_(handle) {}
+
+  bool is_equal(const PlatformThreadHandle& other) const {
+    return handle_ == other.handle_;
+  }
+
+  bool is_null() const {
+    return !handle_;
+  }
+
+  Handle platform_handle() const {
+    return handle_;
+  }
+
+ private:
+  Handle handle_;
+};
+
+const PlatformThreadId kInvalidThreadId(0);
+
+// Valid values for priority of Thread::Options and SimpleThread::Options, and
+// SetCurrentThreadPriority(), listed in increasing order of importance.
+enum class ThreadPriority : int {
+  // Suitable for threads that shouldn't disrupt high priority work.
+  BACKGROUND,
+  // Default priority level.
+  NORMAL,
+  // Suitable for threads which generate data for the display (at ~60Hz).
+  DISPLAY,
+  // Suitable for low-latency, glitch-resistant audio.
+  REALTIME_AUDIO,
+};
+
+// A namespace for low-level thread functions.
+class BASE_EXPORT PlatformThread {
+ public:
+  // Implement this interface to run code on a background thread.  Your
+  // ThreadMain method will be called on the newly created thread.
+  class BASE_EXPORT Delegate {
+   public:
+    virtual void ThreadMain() = 0;
+
+   protected:
+    virtual ~Delegate() = default;
+  };
+
+  // Gets the current thread id, which may be useful for logging purposes.
+  static PlatformThreadId CurrentId();
+
+  // Gets the current thread reference, which can be used to check if
+  // we're on the right thread quickly.
+  static PlatformThreadRef CurrentRef();
+
+  // Get the handle representing the current thread. On Windows, this is a
+  // pseudo handle constant which will always represent the thread using it and
+  // hence should not be shared with other threads nor be used to differentiate
+  // the current thread from another.
+  static PlatformThreadHandle CurrentHandle();
+
+  // Yield the current thread so another thread can be scheduled.
+  static void YieldCurrentThread();
+
+  // Sleeps for the specified duration (real-time; ignores time overrides).
+  // Note: The sleep duration may be in base::Time or base::TimeTicks, depending
+  // on platform. If you're looking to use this in unit tests testing delayed
+  // tasks, this will be unreliable - instead, use
+  // base::test::TaskEnvironment with MOCK_TIME mode.
+  static void Sleep(base::TimeDelta duration);
+
+  // Sets the thread name visible to debuggers/tools. This will try to
+  // initialize the context for current thread unless it's a WorkerThread.
+  static void SetName(const std::string& name);
+
+  // Gets the thread name, if previously set by SetName.
+  static const char* GetName();
+
+  // Creates a new thread.  The |stack_size| parameter can be 0 to indicate
+  // that the default stack size should be used.  Upon success,
+  // |*thread_handle| will be assigned a handle to the newly created thread,
+  // and |delegate|'s ThreadMain method will be executed on the newly created
+  // thread.
+  // NOTE: When you are done with the thread handle, you must call Join to
+  // release system resources associated with the thread.  You must ensure that
+  // the Delegate object outlives the thread.
+  static bool Create(size_t stack_size,
+                     Delegate* delegate,
+                     PlatformThreadHandle* thread_handle) {
+    return CreateWithPriority(stack_size, delegate, thread_handle,
+                              ThreadPriority::NORMAL);
+  }
+
+  // CreateWithPriority() does the same thing as Create() except the priority of
+  // the thread is set based on |priority|.
+  static bool CreateWithPriority(size_t stack_size, Delegate* delegate,
+                                 PlatformThreadHandle* thread_handle,
+                                 ThreadPriority priority);
+
+  // CreateNonJoinable() does the same thing as Create() except the thread
+  // cannot be Join()'d.  Therefore, it also does not output a
+  // PlatformThreadHandle.
+  static bool CreateNonJoinable(size_t stack_size, Delegate* delegate);
+
+  // CreateNonJoinableWithPriority() does the same thing as CreateNonJoinable()
+  // except the priority of the thread is set based on |priority|.
+  static bool CreateNonJoinableWithPriority(size_t stack_size,
+                                            Delegate* delegate,
+                                            ThreadPriority priority);
+
+  // Joins with a thread created via the Create function.  This function blocks
+  // the caller until the designated thread exits.  This will invalidate
+  // |thread_handle|.
+  static void Join(PlatformThreadHandle thread_handle);
+
+  // Detaches and releases the thread handle. The thread is no longer joinable
+  // and |thread_handle| is invalidated after this call.
+  static void Detach(PlatformThreadHandle thread_handle);
+
+  // Returns true if SetCurrentThreadPriority() should be able to increase the
+  // priority of a thread to |priority|.
+  static bool CanIncreaseThreadPriority(ThreadPriority priority);
+
+  // Toggles the current thread's priority at runtime.
+  //
+  // A thread may not be able to raise its priority back up after lowering it if
+  // the process does not have a proper permission, e.g. CAP_SYS_NICE on Linux.
+  // A thread may not be able to lower its priority back down after raising it
+  // to REALTIME_AUDIO.
+  //
+  // This function must not be called from the main thread on Mac. This is to
+  // avoid performance regressions (https://crbug.com/601270).
+  //
+  // Since changing other threads' priority is not permitted in favor of
+  // security, this interface is restricted to change only the current thread
+  // priority (https://crbug.com/399473).
+  static void SetCurrentThreadPriority(ThreadPriority priority);
+
+  static ThreadPriority GetCurrentThreadPriority();
+
+#if defined(OS_LINUX)
+  // Toggles a specific thread's priority at runtime. This can be used to
+  // change the priority of a thread in a different process and will fail
+  // if the calling process does not have proper permissions. The
+  // SetCurrentThreadPriority() function above is preferred in favor of
+  // security but on platforms where sandboxed processes are not allowed to
+  // change priority this function exists to allow a non-sandboxed process
+  // to change the priority of sandboxed threads for improved performance.
+  // Warning: Don't use this for a main thread because that will change the
+  // whole thread group's (i.e. process) priority.
+  static void SetThreadPriority(PlatformThreadId thread_id,
+                                ThreadPriority priority);
+#endif
+
+  // Returns the default thread stack size set by chrome. If we do not
+  // explicitly set default size then returns 0.
+  static size_t GetDefaultThreadStackSize();
+
+ private:
+  static void SetCurrentThreadPriorityImpl(ThreadPriority priority);
+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(PlatformThread);
+};
+
+namespace internal {
+
+// Initializes the "ThreadPriorities" feature. The feature state is only taken
+// into account after this initialization. This initialization must be
+// synchronized with calls to PlatformThread::SetCurrentThreadPriority().
+void InitializeThreadPrioritiesFeature();
+
+}  // namespace internal
+
+}  // namespace base
+
+#endif  // BASE_THREADING_PLATFORM_THREAD_H_
diff --git a/security/sandbox/chromium/base/threading/platform_thread_internal_posix.cc b/security/sandbox/chromium/base/threading/platform_thread_internal_posix.cc
new file mode 100644
index 0000000000..378a24d0d1
--- /dev/null
+++ b/security/sandbox/chromium/base/threading/platform_thread_internal_posix.cc
@@ -0,0 +1,39 @@
+// 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 "base/threading/platform_thread_internal_posix.h"
+
+#include "base/containers/adapters.h"
+#include "base/logging.h"
+
+namespace base {
+
+namespace internal {
+
+int ThreadPriorityToNiceValue(ThreadPriority priority) {
+  for (const auto& pair : kThreadPriorityToNiceValueMap) {
+    if (pair.priority == priority)
+      return pair.nice_value;
+  }
+  NOTREACHED() << "Unknown ThreadPriority";
+  return 0;
+}
+
+ThreadPriority NiceValueToThreadPriority(int nice_value) {
+  // Try to find a priority that best describes |nice_value|. If there isn't
+  // an exact match, this method returns the closest priority whose nice value
+  // is higher (lower priority) than |nice_value|.
+  for (const auto& pair : Reversed(kThreadPriorityToNiceValueMap)) {
+    if (pair.nice_value >= nice_value)
+      return pair.priority;
+  }
+
+  // Reaching here means |nice_value| is more than any of the defined
+  // priorities. The lowest priority is suitable in this case.
+  return ThreadPriority::BACKGROUND;
+}
+
+}  // namespace internal
+
+}  // namespace base
diff --git a/security/sandbox/chromium/base/threading/platform_thread_internal_posix.h b/security/sandbox/chromium/base/threading/platform_thread_internal_posix.h
new file mode 100644
index 0000000000..d248fa9bfd
--- /dev/null
+++ b/security/sandbox/chromium/base/threading/platform_thread_internal_posix.h
@@ -0,0 +1,62 @@
+// 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.
+
+#ifndef BASE_THREADING_PLATFORM_THREAD_INTERNAL_POSIX_H_
+#define BASE_THREADING_PLATFORM_THREAD_INTERNAL_POSIX_H_
+
+#include "base/base_export.h"
+#include "base/optional.h"
+#include "base/threading/platform_thread.h"
+#include "build/build_config.h"
+
+namespace base {
+
+namespace internal {
+
+struct ThreadPriorityToNiceValuePair {
+  ThreadPriority priority;
+  int nice_value;
+};
+// The elements must be listed in the order of increasing priority (lowest
+// priority first), that is, in the order of decreasing nice values (highest
+// nice value first).
+BASE_EXPORT extern
+const ThreadPriorityToNiceValuePair kThreadPriorityToNiceValueMap[4];
+
+// Returns the nice value matching |priority| based on the platform-specific
+// implementation of kThreadPriorityToNiceValueMap.
+int ThreadPriorityToNiceValue(ThreadPriority priority);
+
+// Returns the ThreadPrioirty matching |nice_value| based on the platform-
+// specific implementation of kThreadPriorityToNiceValueMap.
+BASE_EXPORT ThreadPriority NiceValueToThreadPriority(int nice_value);
+
+// If non-nullopt, this return value will be used as the platform-specific
+// result of CanIncreaseThreadPriority().
+Optional<bool> CanIncreaseCurrentThreadPriorityForPlatform(
+    ThreadPriority priority);
+
+// Allows platform specific tweaks to the generic POSIX solution for
+// SetCurrentThreadPriority(). Returns true if the platform-specific
+// implementation handled this |priority| change, false if the generic
+// implementation should instead proceed.
+bool SetCurrentThreadPriorityForPlatform(ThreadPriority priority);
+
+// If non-null, this return value will be used as the platform-specific result
+// of CanIncreaseThreadPriority().
+Optional<ThreadPriority> GetCurrentThreadPriorityForPlatform();
+
+#if defined(OS_LINUX)
+// Current thread id is cached in thread local storage for performance reasons.
+// In some rare cases it's important to clear that cache explicitly (e.g. after
+// going through clone() syscall which does not call pthread_atfork()
+// handlers).
+BASE_EXPORT void ClearTidCache();
+#endif  // defined(OS_LINUX)
+
+}  // namespace internal
+
+}  // namespace base
+
+#endif  // BASE_THREADING_PLATFORM_THREAD_INTERNAL_POSIX_H_
diff --git a/security/sandbox/chromium/base/threading/platform_thread_posix.cc b/security/sandbox/chromium/base/threading/platform_thread_posix.cc
new file mode 100644
index 0000000000..335848e329
--- /dev/null
+++ b/security/sandbox/chromium/base/threading/platform_thread_posix.cc
@@ -0,0 +1,361 @@
+// 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/threading/platform_thread.h"
+
+#include <errno.h>
+#include <pthread.h>
+#include <sched.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <memory>
+
+#include "base/debug/activity_tracker.h"
+#include "base/lazy_instance.h"
+#include "base/logging.h"
+#include "base/no_destructor.h"
+#include "base/threading/platform_thread_internal_posix.h"
+#include "base/threading/scoped_blocking_call.h"
+#include "base/threading/thread_id_name_manager.h"
+#include "build/build_config.h"
+
+#if !defined(OS_MACOSX) && !defined(OS_FUCHSIA) && !defined(OS_NACL)
+#include "base/posix/can_lower_nice_to.h"
+#endif
+
+#if defined(OS_LINUX)
+#include <sys/syscall.h>
+#endif
+
+#if defined(OS_FUCHSIA)
+#include <zircon/process.h>
+#else
+#include <sys/resource.h>
+#endif
+
+namespace base {
+
+void InitThreading();
+void TerminateOnThread();
+size_t GetDefaultThreadStackSize(const pthread_attr_t& attributes);
+
+namespace {
+
+struct ThreadParams {
+  ThreadParams()
+      : delegate(nullptr), joinable(false), priority(ThreadPriority::NORMAL) {}
+
+  PlatformThread::Delegate* delegate;
+  bool joinable;
+  ThreadPriority priority;
+};
+
+void* ThreadFunc(void* params) {
+  PlatformThread::Delegate* delegate = nullptr;
+
+  {
+    std::unique_ptr<ThreadParams> thread_params(
+        static_cast<ThreadParams*>(params));
+
+    delegate = thread_params->delegate;
+    if (!thread_params->joinable)
+      base::ThreadRestrictions::SetSingletonAllowed(false);
+
+#if !defined(OS_NACL)
+    // Threads on linux/android may inherit their priority from the thread
+    // where they were created. This explicitly sets the priority of all new
+    // threads.
+    PlatformThread::SetCurrentThreadPriority(thread_params->priority);
+#endif
+  }
+
+  ThreadIdNameManager::GetInstance()->RegisterThread(
+      PlatformThread::CurrentHandle().platform_handle(),
+      PlatformThread::CurrentId());
+
+  delegate->ThreadMain();
+
+  ThreadIdNameManager::GetInstance()->RemoveName(
+      PlatformThread::CurrentHandle().platform_handle(),
+      PlatformThread::CurrentId());
+
+  base::TerminateOnThread();
+  return nullptr;
+}
+
+bool CreateThread(size_t stack_size,
+                  bool joinable,
+                  PlatformThread::Delegate* delegate,
+                  PlatformThreadHandle* thread_handle,
+                  ThreadPriority priority) {
+  DCHECK(thread_handle);
+  base::InitThreading();
+
+  pthread_attr_t attributes;
+  pthread_attr_init(&attributes);
+
+  // Pthreads are joinable by default, so only specify the detached
+  // attribute if the thread should be non-joinable.
+  if (!joinable)
+    pthread_attr_setdetachstate(&attributes, PTHREAD_CREATE_DETACHED);
+
+  // Get a better default if available.
+  if (stack_size == 0)
+    stack_size = base::GetDefaultThreadStackSize(attributes);
+
+  if (stack_size > 0)
+    pthread_attr_setstacksize(&attributes, stack_size);
+
+  std::unique_ptr<ThreadParams> params(new ThreadParams);
+  params->delegate = delegate;
+  params->joinable = joinable;
+  params->priority = priority;
+
+  pthread_t handle;
+  int err = pthread_create(&handle, &attributes, ThreadFunc, params.get());
+  bool success = !err;
+  if (success) {
+    // ThreadParams should be deleted on the created thread after used.
+    ignore_result(params.release());
+  } else {
+    // Value of |handle| is undefined if pthread_create fails.
+    handle = 0;
+    errno = err;
+    PLOG(ERROR) << "pthread_create";
+  }
+  *thread_handle = PlatformThreadHandle(handle);
+
+  pthread_attr_destroy(&attributes);
+
+  return success;
+}
+
+#if defined(OS_LINUX)
+
+// Store the thread ids in local storage since calling the SWI can
+// expensive and PlatformThread::CurrentId is used liberally. Clear
+// the stored value after a fork() because forking changes the thread
+// id. Forking without going through fork() (e.g. clone()) is not
+// supported, but there is no known usage. Using thread_local is
+// fine here (despite being banned) since it is going to be allowed
+// but is blocked on a clang bug for Mac (https://crbug.com/829078)
+// and we can't use ThreadLocalStorage because of re-entrancy due to
+// CHECK/DCHECKs.
+thread_local pid_t g_thread_id = -1;
+
+class InitAtFork {
+ public:
+  InitAtFork() { pthread_atfork(nullptr, nullptr, internal::ClearTidCache); }
+};
+
+#endif  // defined(OS_LINUX)
+
+}  // namespace
+
+#if defined(OS_LINUX)
+
+namespace internal {
+
+void ClearTidCache() {
+  g_thread_id = -1;
+}
+
+}  // namespace internal
+
+#endif  // defined(OS_LINUX)
+
+// static
+PlatformThreadId PlatformThread::CurrentId() {
+  // Pthreads doesn't have the concept of a thread ID, so we have to reach down
+  // into the kernel.
+#if defined(OS_MACOSX)
+  return pthread_mach_thread_np(pthread_self());
+#elif defined(OS_LINUX)
+  static NoDestructor<InitAtFork> init_at_fork;
+  if (g_thread_id == -1) {
+    g_thread_id = syscall(__NR_gettid);
+  } else {
+    DCHECK_EQ(g_thread_id, syscall(__NR_gettid))
+        << "Thread id stored in TLS is different from thread id returned by "
+           "the system. It is likely that the process was forked without going "
+           "through fork().";
+  }
+  return g_thread_id;
+#elif defined(OS_ANDROID)
+  return gettid();
+#elif defined(OS_FUCHSIA)
+  return zx_thread_self();
+#elif defined(OS_SOLARIS) || defined(OS_QNX)
+  return pthread_self();
+#elif defined(OS_NACL) && defined(__GLIBC__)
+  return pthread_self();
+#elif defined(OS_NACL) && !defined(__GLIBC__)
+  // Pointers are 32-bits in NaCl.
+  return reinterpret_cast<int32_t>(pthread_self());
+#elif defined(OS_POSIX) && defined(OS_AIX)
+  return pthread_self();
+#elif defined(OS_POSIX) && !defined(OS_AIX)
+  return reinterpret_cast<int64_t>(pthread_self());
+#endif
+}
+
+// static
+PlatformThreadRef PlatformThread::CurrentRef() {
+  return PlatformThreadRef(pthread_self());
+}
+
+// static
+PlatformThreadHandle PlatformThread::CurrentHandle() {
+  return PlatformThreadHandle(pthread_self());
+}
+
+// static
+void PlatformThread::YieldCurrentThread() {
+  sched_yield();
+}
+
+// static
+void PlatformThread::Sleep(TimeDelta duration) {
+  struct timespec sleep_time, remaining;
+
+  // Break the duration into seconds and nanoseconds.
+  // NOTE: TimeDelta's microseconds are int64s while timespec's
+  // nanoseconds are longs, so this unpacking must prevent overflow.
+  sleep_time.tv_sec = duration.InSeconds();
+  duration -= TimeDelta::FromSeconds(sleep_time.tv_sec);
+  sleep_time.tv_nsec = duration.InMicroseconds() * 1000;  // nanoseconds
+
+  while (nanosleep(&sleep_time, &remaining) == -1 && errno == EINTR)
+    sleep_time = remaining;
+}
+
+// static
+const char* PlatformThread::GetName() {
+  return ThreadIdNameManager::GetInstance()->GetName(CurrentId());
+}
+
+// static
+bool PlatformThread::CreateWithPriority(size_t stack_size, Delegate* delegate,
+                                        PlatformThreadHandle* thread_handle,
+                                        ThreadPriority priority) {
+  return CreateThread(stack_size, true /* joinable thread */, delegate,
+                      thread_handle, priority);
+}
+
+// static
+bool PlatformThread::CreateNonJoinable(size_t stack_size, Delegate* delegate) {
+  return CreateNonJoinableWithPriority(stack_size, delegate,
+                                       ThreadPriority::NORMAL);
+}
+
+// static
+bool PlatformThread::CreateNonJoinableWithPriority(size_t stack_size,
+                                                   Delegate* delegate,
+                                                   ThreadPriority priority) {
+  PlatformThreadHandle unused;
+
+  bool result = CreateThread(stack_size, false /* non-joinable thread */,
+                             delegate, &unused, priority);
+  return result;
+}
+
+// static
+void PlatformThread::Join(PlatformThreadHandle thread_handle) {
+  // Record the event that this thread is blocking upon (for hang diagnosis).
+  base::debug::ScopedThreadJoinActivity thread_activity(&thread_handle);
+
+  // Joining another thread may block the current thread for a long time, since
+  // the thread referred to by |thread_handle| may still be running long-lived /
+  // blocking tasks.
+  base::internal::ScopedBlockingCallWithBaseSyncPrimitives scoped_blocking_call(
+      FROM_HERE, base::BlockingType::MAY_BLOCK);
+  CHECK_EQ(0, pthread_join(thread_handle.platform_handle(), nullptr));
+}
+
+// static
+void PlatformThread::Detach(PlatformThreadHandle thread_handle) {
+  CHECK_EQ(0, pthread_detach(thread_handle.platform_handle()));
+}
+
+// Mac and Fuchsia have their own Set/GetCurrentThreadPriority()
+// implementations.
+#if !defined(OS_MACOSX) && !defined(OS_FUCHSIA)
+
+// static
+bool PlatformThread::CanIncreaseThreadPriority(ThreadPriority priority) {
+#if defined(OS_NACL)
+  return false;
+#else
+  auto platform_specific_ability =
+      internal::CanIncreaseCurrentThreadPriorityForPlatform(priority);
+  if (platform_specific_ability)
+    return platform_specific_ability.value();
+
+  return internal::CanLowerNiceTo(
+      internal::ThreadPriorityToNiceValue(priority));
+#endif  // defined(OS_NACL)
+}
+
+// static
+void PlatformThread::SetCurrentThreadPriorityImpl(ThreadPriority priority) {
+#if defined(OS_NACL)
+  NOTIMPLEMENTED();
+#else
+  if (internal::SetCurrentThreadPriorityForPlatform(priority))
+    return;
+
+  // setpriority(2) should change the whole thread group's (i.e. process)
+  // priority. However, as stated in the bugs section of
+  // http://man7.org/linux/man-pages/man2/getpriority.2.html: "under the current
+  // Linux/NPTL implementation of POSIX threads, the nice value is a per-thread
+  // attribute". Also, 0 is prefered to the current thread id since it is
+  // equivalent but makes sandboxing easier (https://crbug.com/399473).
+  const int nice_setting = internal::ThreadPriorityToNiceValue(priority);
+  if (setpriority(PRIO_PROCESS, 0, nice_setting)) {
+    DVPLOG(1) << "Failed to set nice value of thread ("
+              << PlatformThread::CurrentId() << ") to " << nice_setting;
+  }
+#endif  // defined(OS_NACL)
+}
+
+// static
+ThreadPriority PlatformThread::GetCurrentThreadPriority() {
+#if defined(OS_NACL)
+  NOTIMPLEMENTED();
+  return ThreadPriority::NORMAL;
+#else
+  // Mirrors SetCurrentThreadPriority()'s implementation.
+  auto platform_specific_priority =
+      internal::GetCurrentThreadPriorityForPlatform();
+  if (platform_specific_priority)
+    return platform_specific_priority.value();
+
+  // Need to clear errno before calling getpriority():
+  // http://man7.org/linux/man-pages/man2/getpriority.2.html
+  errno = 0;
+  int nice_value = getpriority(PRIO_PROCESS, 0);
+  if (errno != 0) {
+    DVPLOG(1) << "Failed to get nice value of thread ("
+              << PlatformThread::CurrentId() << ")";
+    return ThreadPriority::NORMAL;
+  }
+
+  return internal::NiceValueToThreadPriority(nice_value);
+#endif  // !defined(OS_NACL)
+}
+
+#endif  // !defined(OS_MACOSX) && !defined(OS_FUCHSIA)
+
+// static
+size_t PlatformThread::GetDefaultThreadStackSize() {
+  pthread_attr_t attributes;
+  pthread_attr_init(&attributes);
+  return base::GetDefaultThreadStackSize(attributes);
+}
+
+}  // namespace base
diff --git a/security/sandbox/chromium/base/threading/platform_thread_win.cc b/security/sandbox/chromium/base/threading/platform_thread_win.cc
new file mode 100644
index 0000000000..0bcf6db247
--- /dev/null
+++ b/security/sandbox/chromium/base/threading/platform_thread_win.cc
@@ -0,0 +1,463 @@
+// 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/threading/platform_thread_win.h"
+
+#include <stddef.h>
+
+#include "base/debug/activity_tracker.h"
+#include "base/debug/alias.h"
+#include "base/debug/crash_logging.h"
+#include "base/debug/profiler.h"
+#include "base/logging.h"
+#include "base/metrics/histogram_macros.h"
+#include "base/process/memory.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/strings/utf_string_conversions.h"
+#include "base/threading/scoped_blocking_call.h"
+#include "base/threading/thread_id_name_manager.h"
+#include "base/threading/thread_restrictions.h"
+#include "base/time/time_override.h"
+#include "base/win/scoped_handle.h"
+#include "base/win/windows_version.h"
+#include "build/build_config.h"
+
+#include <windows.h>
+
+namespace base {
+
+namespace {
+
+// The most common value returned by ::GetThreadPriority() after background
+// thread mode is enabled on Windows 7.
+constexpr int kWin7BackgroundThreadModePriority = 4;
+
+// Value sometimes returned by ::GetThreadPriority() after thread priority is
+// set to normal on Windows 7.
+constexpr int kWin7NormalPriority = 3;
+
+// These values are sometimes returned by ::GetThreadPriority().
+constexpr int kWinNormalPriority1 = 5;
+constexpr int kWinNormalPriority2 = 6;
+
+// The information on how to set the thread name comes from
+// a MSDN article: http://msdn2.microsoft.com/en-us/library/xcb2z8hs.aspx
+const DWORD kVCThreadNameException = 0x406D1388;
+
+typedef struct tagTHREADNAME_INFO {
+  DWORD dwType;  // Must be 0x1000.
+  LPCSTR szName;  // Pointer to name (in user addr space).
+  DWORD dwThreadID;  // Thread ID (-1=caller thread).
+  DWORD dwFlags;  // Reserved for future use, must be zero.
+} THREADNAME_INFO;
+
+// The SetThreadDescription API was brought in version 1607 of Windows 10.
+typedef HRESULT(WINAPI* SetThreadDescription)(HANDLE hThread,
+                                              PCWSTR lpThreadDescription);
+
+// This function has try handling, so it is separated out of its caller.
+void SetNameInternal(PlatformThreadId thread_id, const char* name) {
+  //This function is only used for debugging purposes, as you can find by its caller
+#ifndef __MINGW32__
+  THREADNAME_INFO info;
+  info.dwType = 0x1000;
+  info.szName = name;
+  info.dwThreadID = thread_id;
+  info.dwFlags = 0;
+
+  __try {
+    RaiseException(kVCThreadNameException, 0, sizeof(info)/sizeof(DWORD),
+                   reinterpret_cast<DWORD_PTR*>(&info));
+  } __except(EXCEPTION_CONTINUE_EXECUTION) {
+  }
+#endif
+}
+
+struct ThreadParams {
+  PlatformThread::Delegate* delegate;
+  bool joinable;
+  ThreadPriority priority;
+};
+
+DWORD __stdcall ThreadFunc(void* params) {
+  ThreadParams* thread_params = static_cast<ThreadParams*>(params);
+  PlatformThread::Delegate* delegate = thread_params->delegate;
+  if (!thread_params->joinable)
+    base::ThreadRestrictions::SetSingletonAllowed(false);
+
+  if (thread_params->priority != ThreadPriority::NORMAL)
+    PlatformThread::SetCurrentThreadPriority(thread_params->priority);
+
+  // Retrieve a copy of the thread handle to use as the key in the
+  // thread name mapping.
+  PlatformThreadHandle::Handle platform_handle;
+  BOOL did_dup = DuplicateHandle(GetCurrentProcess(),
+                                GetCurrentThread(),
+                                GetCurrentProcess(),
+                                &platform_handle,
+                                0,
+                                FALSE,
+                                DUPLICATE_SAME_ACCESS);
+
+  win::ScopedHandle scoped_platform_handle;
+
+  if (did_dup) {
+    scoped_platform_handle.Set(platform_handle);
+    ThreadIdNameManager::GetInstance()->RegisterThread(
+        scoped_platform_handle.Get(),
+        PlatformThread::CurrentId());
+  }
+
+  delete thread_params;
+  delegate->ThreadMain();
+
+  if (did_dup) {
+    ThreadIdNameManager::GetInstance()->RemoveName(
+        scoped_platform_handle.Get(),
+        PlatformThread::CurrentId());
+  }
+
+  return 0;
+}
+
+// CreateThreadInternal() matches PlatformThread::CreateWithPriority(), except
+// that |out_thread_handle| may be nullptr, in which case a non-joinable thread
+// is created.
+bool CreateThreadInternal(size_t stack_size,
+                          PlatformThread::Delegate* delegate,
+                          PlatformThreadHandle* out_thread_handle,
+                          ThreadPriority priority) {
+  unsigned int flags = 0;
+  if (stack_size > 0) {
+    flags = STACK_SIZE_PARAM_IS_A_RESERVATION;
+#if defined(ARCH_CPU_32_BITS)
+  } else {
+    // The process stack size is increased to give spaces to |RendererMain| in
+    // |chrome/BUILD.gn|, but keep the default stack size of other threads to
+    // 1MB for the address space pressure.
+    flags = STACK_SIZE_PARAM_IS_A_RESERVATION;
+    stack_size = 1024 * 1024;
+#endif
+  }
+
+  ThreadParams* params = new ThreadParams;
+  params->delegate = delegate;
+  params->joinable = out_thread_handle != nullptr;
+  params->priority = priority;
+
+  // Using CreateThread here vs _beginthreadex makes thread creation a bit
+  // faster and doesn't require the loader lock to be available.  Our code will
+  // have to work running on CreateThread() threads anyway, since we run code on
+  // the Windows thread pool, etc.  For some background on the difference:
+  // http://www.microsoft.com/msj/1099/win32/win321099.aspx
+  void* thread_handle =
+      ::CreateThread(nullptr, stack_size, ThreadFunc, params, flags, nullptr);
+
+  if (!thread_handle) {
+    DWORD last_error = ::GetLastError();
+
+    switch (last_error) {
+      case ERROR_NOT_ENOUGH_MEMORY:
+      case ERROR_OUTOFMEMORY:
+      case ERROR_COMMITMENT_LIMIT:
+        TerminateBecauseOutOfMemory(stack_size);
+        break;
+
+      default:
+        static auto* last_error_crash_key = debug::AllocateCrashKeyString(
+            "create_thread_last_error", debug::CrashKeySize::Size32);
+        debug::SetCrashKeyString(last_error_crash_key,
+                                 base::NumberToString(last_error));
+        break;
+    }
+
+    delete params;
+    return false;
+  }
+
+  if (out_thread_handle)
+    *out_thread_handle = PlatformThreadHandle(thread_handle);
+  else
+    CloseHandle(thread_handle);
+  return true;
+}
+
+}  // namespace
+
+namespace internal {
+
+void AssertMemoryPriority(HANDLE thread, int memory_priority) {
+#if DCHECK_IS_ON()
+  static const auto get_thread_information_fn =
+      reinterpret_cast<decltype(&::GetThreadInformation)>(::GetProcAddress(
+          ::GetModuleHandle(L"Kernel32.dll"), "GetThreadInformation"));
+
+  if (!get_thread_information_fn) {
+    DCHECK_EQ(win::GetVersion(), win::Version::WIN7);
+    return;
+  }
+
+  MEMORY_PRIORITY_INFORMATION memory_priority_information = {};
+  DCHECK(get_thread_information_fn(thread, ::ThreadMemoryPriority,
+                                   &memory_priority_information,
+                                   sizeof(memory_priority_information)));
+
+  DCHECK_EQ(memory_priority,
+            static_cast<int>(memory_priority_information.MemoryPriority));
+#endif
+}
+
+}  // namespace internal
+
+// static
+PlatformThreadId PlatformThread::CurrentId() {
+  return ::GetCurrentThreadId();
+}
+
+// static
+PlatformThreadRef PlatformThread::CurrentRef() {
+  return PlatformThreadRef(::GetCurrentThreadId());
+}
+
+// static
+PlatformThreadHandle PlatformThread::CurrentHandle() {
+  return PlatformThreadHandle(::GetCurrentThread());
+}
+
+// static
+void PlatformThread::YieldCurrentThread() {
+  ::Sleep(0);
+}
+
+// static
+void PlatformThread::Sleep(TimeDelta duration) {
+  // When measured with a high resolution clock, Sleep() sometimes returns much
+  // too early. We may need to call it repeatedly to get the desired duration.
+  // PlatformThread::Sleep doesn't support mock-time, so this always uses
+  // real-time.
+  const TimeTicks end = subtle::TimeTicksNowIgnoringOverride() + duration;
+  for (TimeTicks now = subtle::TimeTicksNowIgnoringOverride(); now < end;
+       now = subtle::TimeTicksNowIgnoringOverride()) {
+    ::Sleep(static_cast<DWORD>((end - now).InMillisecondsRoundedUp()));
+  }
+}
+
+// static
+void PlatformThread::SetName(const std::string& name) {
+  ThreadIdNameManager::GetInstance()->SetName(name);
+
+  // The SetThreadDescription API works even if no debugger is attached.
+  static auto set_thread_description_func =
+      reinterpret_cast<SetThreadDescription>(::GetProcAddress(
+          ::GetModuleHandle(L"Kernel32.dll"), "SetThreadDescription"));
+  if (set_thread_description_func) {
+    set_thread_description_func(::GetCurrentThread(),
+                                base::UTF8ToWide(name).c_str());
+  }
+
+  // The debugger needs to be around to catch the name in the exception.  If
+  // there isn't a debugger, we are just needlessly throwing an exception.
+  if (!::IsDebuggerPresent())
+    return;
+
+  SetNameInternal(CurrentId(), name.c_str());
+}
+
+// static
+const char* PlatformThread::GetName() {
+  return ThreadIdNameManager::GetInstance()->GetName(CurrentId());
+}
+
+// static
+bool PlatformThread::CreateWithPriority(size_t stack_size, Delegate* delegate,
+                                        PlatformThreadHandle* thread_handle,
+                                        ThreadPriority priority) {
+  DCHECK(thread_handle);
+  return CreateThreadInternal(stack_size, delegate, thread_handle, priority);
+}
+
+// static
+bool PlatformThread::CreateNonJoinable(size_t stack_size, Delegate* delegate) {
+  return CreateNonJoinableWithPriority(stack_size, delegate,
+                                       ThreadPriority::NORMAL);
+}
+
+// static
+bool PlatformThread::CreateNonJoinableWithPriority(size_t stack_size,
+                                                   Delegate* delegate,
+                                                   ThreadPriority priority) {
+  return CreateThreadInternal(stack_size, delegate, nullptr /* non-joinable */,
+                              priority);
+}
+
+// static
+void PlatformThread::Join(PlatformThreadHandle thread_handle) {
+  DCHECK(thread_handle.platform_handle());
+
+  DWORD thread_id = 0;
+  thread_id = ::GetThreadId(thread_handle.platform_handle());
+  DWORD last_error = 0;
+  if (!thread_id)
+    last_error = ::GetLastError();
+
+  // Record information about the exiting thread in case joining hangs.
+  base::debug::Alias(&thread_id);
+  base::debug::Alias(&last_error);
+
+  // Record the event that this thread is blocking upon (for hang diagnosis).
+  base::debug::ScopedThreadJoinActivity thread_activity(&thread_handle);
+
+  base::internal::ScopedBlockingCallWithBaseSyncPrimitives scoped_blocking_call(
+      FROM_HERE, base::BlockingType::MAY_BLOCK);
+
+  // Wait for the thread to exit.  It should already have terminated but make
+  // sure this assumption is valid.
+  CHECK_EQ(WAIT_OBJECT_0,
+           WaitForSingleObject(thread_handle.platform_handle(), INFINITE));
+  CloseHandle(thread_handle.platform_handle());
+}
+
+// static
+void PlatformThread::Detach(PlatformThreadHandle thread_handle) {
+  CloseHandle(thread_handle.platform_handle());
+}
+
+// static
+bool PlatformThread::CanIncreaseThreadPriority(ThreadPriority priority) {
+  return true;
+}
+
+// static
+void PlatformThread::SetCurrentThreadPriorityImpl(ThreadPriority priority) {
+  PlatformThreadHandle::Handle thread_handle =
+      PlatformThread::CurrentHandle().platform_handle();
+
+  if (priority != ThreadPriority::BACKGROUND) {
+    // Exit background mode if the new priority is not BACKGROUND. This is a
+    // no-op if not in background mode.
+    ::SetThreadPriority(thread_handle, THREAD_MODE_BACKGROUND_END);
+    internal::AssertMemoryPriority(thread_handle, MEMORY_PRIORITY_NORMAL);
+  }
+
+  int desired_priority = THREAD_PRIORITY_ERROR_RETURN;
+  switch (priority) {
+    case ThreadPriority::BACKGROUND:
+      // Using THREAD_MODE_BACKGROUND_BEGIN instead of THREAD_PRIORITY_LOWEST
+      // improves input latency and navigation time. See
+      // https://docs.google.com/document/d/16XrOwuwTwKWdgPbcKKajTmNqtB4Am8TgS9GjbzBYLc0
+      //
+      // MSDN recommends THREAD_MODE_BACKGROUND_BEGIN for threads that perform
+      // background work, as it reduces disk and memory priority in addition to
+      // CPU priority.
+      desired_priority = THREAD_MODE_BACKGROUND_BEGIN;
+      break;
+    case ThreadPriority::NORMAL:
+      desired_priority = THREAD_PRIORITY_NORMAL;
+      break;
+    case ThreadPriority::DISPLAY:
+      desired_priority = THREAD_PRIORITY_ABOVE_NORMAL;
+      break;
+    case ThreadPriority::REALTIME_AUDIO:
+      desired_priority = THREAD_PRIORITY_TIME_CRITICAL;
+      break;
+    default:
+      NOTREACHED() << "Unknown priority.";
+      break;
+  }
+  DCHECK_NE(desired_priority, THREAD_PRIORITY_ERROR_RETURN);
+
+#if DCHECK_IS_ON()
+  const BOOL success =
+#endif
+      ::SetThreadPriority(thread_handle, desired_priority);
+  DPLOG_IF(ERROR, !success) << "Failed to set thread priority to "
+                            << desired_priority;
+
+  if (priority == ThreadPriority::BACKGROUND) {
+    // In a background process, THREAD_MODE_BACKGROUND_BEGIN lowers the memory
+    // and I/O priorities but not the CPU priority (kernel bug?). Use
+    // THREAD_PRIORITY_LOWEST to also lower the CPU priority.
+    // https://crbug.com/901483
+    if (GetCurrentThreadPriority() != ThreadPriority::BACKGROUND) {
+      ::SetThreadPriority(thread_handle, THREAD_PRIORITY_LOWEST);
+      // Make sure that using THREAD_PRIORITY_LOWEST didn't affect the memory
+      // priority set by THREAD_MODE_BACKGROUND_BEGIN. There is no practical
+      // way to verify the I/O priority.
+      internal::AssertMemoryPriority(thread_handle, MEMORY_PRIORITY_VERY_LOW);
+    }
+  }
+
+  DCHECK_EQ(GetCurrentThreadPriority(), priority);
+}
+
+// static
+ThreadPriority PlatformThread::GetCurrentThreadPriority() {
+  static_assert(
+      THREAD_PRIORITY_IDLE < 0,
+      "THREAD_PRIORITY_IDLE is >= 0 and will incorrectly cause errors.");
+  static_assert(
+      THREAD_PRIORITY_LOWEST < 0,
+      "THREAD_PRIORITY_LOWEST is >= 0 and will incorrectly cause errors.");
+  static_assert(THREAD_PRIORITY_BELOW_NORMAL < 0,
+                "THREAD_PRIORITY_BELOW_NORMAL is >= 0 and will incorrectly "
+                "cause errors.");
+  static_assert(
+      THREAD_PRIORITY_NORMAL == 0,
+      "The logic below assumes that THREAD_PRIORITY_NORMAL is zero. If it is "
+      "not, ThreadPriority::BACKGROUND may be incorrectly detected.");
+  static_assert(THREAD_PRIORITY_ABOVE_NORMAL >= 0,
+                "THREAD_PRIORITY_ABOVE_NORMAL is < 0 and will incorrectly be "
+                "translated to ThreadPriority::BACKGROUND.");
+  static_assert(THREAD_PRIORITY_HIGHEST >= 0,
+                "THREAD_PRIORITY_HIGHEST is < 0 and will incorrectly be "
+                "translated to ThreadPriority::BACKGROUND.");
+  static_assert(THREAD_PRIORITY_TIME_CRITICAL >= 0,
+                "THREAD_PRIORITY_TIME_CRITICAL is < 0 and will incorrectly be "
+                "translated to ThreadPriority::BACKGROUND.");
+  static_assert(THREAD_PRIORITY_ERROR_RETURN >= 0,
+                "THREAD_PRIORITY_ERROR_RETURN is < 0 and will incorrectly be "
+                "translated to ThreadPriority::BACKGROUND.");
+
+  const int priority =
+      ::GetThreadPriority(PlatformThread::CurrentHandle().platform_handle());
+
+  // Negative values represent a background priority. We have observed -3, -4,
+  // -6 when THREAD_MODE_BACKGROUND_* is used. THREAD_PRIORITY_IDLE,
+  // THREAD_PRIORITY_LOWEST and THREAD_PRIORITY_BELOW_NORMAL are other possible
+  // negative values.
+  if (priority < THREAD_PRIORITY_NORMAL)
+    return ThreadPriority::BACKGROUND;
+
+  switch (priority) {
+    case kWin7BackgroundThreadModePriority:
+      DCHECK_EQ(win::GetVersion(), win::Version::WIN7);
+      return ThreadPriority::BACKGROUND;
+    case kWin7NormalPriority:
+      DCHECK_EQ(win::GetVersion(), win::Version::WIN7);
+      FALLTHROUGH;
+    case THREAD_PRIORITY_NORMAL:
+      return ThreadPriority::NORMAL;
+    case kWinNormalPriority1:
+      FALLTHROUGH;
+    case kWinNormalPriority2:
+      return ThreadPriority::NORMAL;
+    case THREAD_PRIORITY_ABOVE_NORMAL:
+    case THREAD_PRIORITY_HIGHEST:
+      return ThreadPriority::DISPLAY;
+    case THREAD_PRIORITY_TIME_CRITICAL:
+      return ThreadPriority::REALTIME_AUDIO;
+    case THREAD_PRIORITY_ERROR_RETURN:
+      DPCHECK(false) << "::GetThreadPriority error";
+  }
+
+  NOTREACHED() << "::GetThreadPriority returned " << priority << ".";
+  return ThreadPriority::NORMAL;
+}
+
+// static
+size_t PlatformThread::GetDefaultThreadStackSize() {
+  return 0;
+}
+
+}  // namespace base
diff --git a/security/sandbox/chromium/base/threading/platform_thread_win.h b/security/sandbox/chromium/base/threading/platform_thread_win.h
new file mode 100644
index 0000000000..3e833178e3
--- /dev/null
+++ b/security/sandbox/chromium/base/threading/platform_thread_win.h
@@ -0,0 +1,23 @@
+// Copyright 2018 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.
+
+#ifndef BASE_THREADING_PLATFORM_THREAD_WIN_H_
+#define BASE_THREADING_PLATFORM_THREAD_WIN_H_
+
+#include "base/threading/platform_thread.h"
+
+#include "base/base_export.h"
+
+namespace base {
+namespace internal {
+
+// Assert that the memory priority of |thread| is |memory_priority|. No-op on
+// Windows 7 because ::GetThreadInformation() is not available. Exposed for unit
+// tests.
+BASE_EXPORT void AssertMemoryPriority(HANDLE thread, int memory_priority);
+
+}  // namespace internal
+}  // namespace base
+
+#endif  // BASE_THREADING_PLATFORM_THREAD_WIN_H_
diff --git a/security/sandbox/chromium/base/threading/thread_checker_impl.h b/security/sandbox/chromium/base/threading/thread_checker_impl.h
new file mode 100644
index 0000000000..b325db6ae8
--- /dev/null
+++ b/security/sandbox/chromium/base/threading/thread_checker_impl.h
@@ -0,0 +1,74 @@
+// Copyright (c) 2011 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.
+
+#ifndef BASE_THREADING_THREAD_CHECKER_IMPL_H_
+#define BASE_THREADING_THREAD_CHECKER_IMPL_H_
+
+#include "base/base_export.h"
+#include "base/compiler_specific.h"
+#include "base/sequence_token.h"
+#include "base/synchronization/lock.h"
+#include "base/thread_annotations.h"
+#include "base/threading/platform_thread.h"
+
+namespace base {
+
+// Real implementation of ThreadChecker, for use in debug mode, or for temporary
+// use in release mode (e.g. to CHECK on a threading issue seen only in the
+// wild).
+//
+// Note: You should almost always use the ThreadChecker class to get the right
+// version for your build configuration.
+// Note: This is only a check, not a "lock". It is marked "LOCKABLE" only in
+// order to support thread_annotations.h.
+class LOCKABLE BASE_EXPORT ThreadCheckerImpl {
+ public:
+  ThreadCheckerImpl();
+  ~ThreadCheckerImpl();
+
+  // Allow move construct/assign. This must be called on |other|'s associated
+  // thread and assignment can only be made into a ThreadCheckerImpl which is
+  // detached or already associated with the current thread. This isn't
+  // thread-safe (|this| and |other| shouldn't be in use while this move is
+  // performed). If the assignment was legal, the resulting ThreadCheckerImpl
+  // will be bound to the current thread and |other| will be detached.
+  ThreadCheckerImpl(ThreadCheckerImpl&& other);
+  ThreadCheckerImpl& operator=(ThreadCheckerImpl&& other);
+
+  bool CalledOnValidThread() const WARN_UNUSED_RESULT;
+
+  // Changes the thread that is checked for in CalledOnValidThread.  This may
+  // be useful when an object may be created on one thread and then used
+  // exclusively on another thread.
+  void DetachFromThread();
+
+ private:
+  void EnsureAssignedLockRequired() const EXCLUSIVE_LOCKS_REQUIRED(lock_);
+
+  // Members are mutable so that CalledOnValidThread() can set them.
+
+  // Synchronizes access to all members.
+  mutable base::Lock lock_;
+
+  // Thread on which CalledOnValidThread() may return true.
+  mutable PlatformThreadRef thread_id_ GUARDED_BY(lock_);
+
+  // TaskToken for which CalledOnValidThread() always returns true. This allows
+  // CalledOnValidThread() to return true when called multiple times from the
+  // same task, even if it's not running in a single-threaded context itself
+  // (allowing usage of ThreadChecker objects on the stack in the scope of one-
+  // off tasks). Note: CalledOnValidThread() may return true even if the current
+  // TaskToken is not equal to this.
+  mutable TaskToken task_token_ GUARDED_BY(lock_);
+
+  // SequenceToken for which CalledOnValidThread() may return true. Used to
+  // ensure that CalledOnValidThread() doesn't return true for ThreadPool
+  // tasks that happen to run on the same thread but weren't posted to the same
+  // SingleThreadTaskRunner.
+  mutable SequenceToken sequence_token_ GUARDED_BY(lock_);
+};
+
+}  // namespace base
+
+#endif  // BASE_THREADING_THREAD_CHECKER_IMPL_H_
diff --git a/security/sandbox/chromium/base/threading/thread_collision_warner.cc b/security/sandbox/chromium/base/threading/thread_collision_warner.cc
new file mode 100644
index 0000000000..547e11ca66
--- /dev/null
+++ b/security/sandbox/chromium/base/threading/thread_collision_warner.cc
@@ -0,0 +1,64 @@
+// Copyright (c) 2010 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/threading/thread_collision_warner.h"
+
+#include "base/logging.h"
+#include "base/threading/platform_thread.h"
+
+namespace base {
+
+void DCheckAsserter::warn() {
+  NOTREACHED() << "Thread Collision";
+}
+
+static subtle::Atomic32 CurrentThread() {
+  const PlatformThreadId current_thread_id = PlatformThread::CurrentId();
+  // We need to get the thread id into an atomic data type. This might be a
+  // truncating conversion, but any loss-of-information just increases the
+  // chance of a fault negative, not a false positive.
+  const subtle::Atomic32 atomic_thread_id =
+      static_cast<subtle::Atomic32>(current_thread_id);
+
+  return atomic_thread_id;
+}
+
+void ThreadCollisionWarner::EnterSelf() {
+  // If the active thread is 0 then I'll write the current thread ID
+  // if two or more threads arrive here only one will succeed to
+  // write on valid_thread_id_ the current thread ID.
+  subtle::Atomic32 current_thread_id = CurrentThread();
+
+  int previous_value = subtle::NoBarrier_CompareAndSwap(&valid_thread_id_,
+                                                        0,
+                                                        current_thread_id);
+  if (previous_value != 0 && previous_value != current_thread_id) {
+    // gotcha! a thread is trying to use the same class and that is
+    // not current thread.
+    asserter_->warn();
+  }
+
+  subtle::NoBarrier_AtomicIncrement(&counter_, 1);
+}
+
+void ThreadCollisionWarner::Enter() {
+  subtle::Atomic32 current_thread_id = CurrentThread();
+
+  if (subtle::NoBarrier_CompareAndSwap(&valid_thread_id_,
+                                       0,
+                                       current_thread_id) != 0) {
+    // gotcha! another thread is trying to use the same class.
+    asserter_->warn();
+  }
+
+  subtle::NoBarrier_AtomicIncrement(&counter_, 1);
+}
+
+void ThreadCollisionWarner::Leave() {
+  if (subtle::Barrier_AtomicIncrement(&counter_, -1) == 0) {
+    subtle::NoBarrier_Store(&valid_thread_id_, 0);
+  }
+}
+
+}  // namespace base
diff --git a/security/sandbox/chromium/base/threading/thread_collision_warner.h b/security/sandbox/chromium/base/threading/thread_collision_warner.h
new file mode 100644
index 0000000000..7f7443b21d
--- /dev/null
+++ b/security/sandbox/chromium/base/threading/thread_collision_warner.h
@@ -0,0 +1,252 @@
+// 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.
+
+#ifndef BASE_THREADING_THREAD_COLLISION_WARNER_H_
+#define BASE_THREADING_THREAD_COLLISION_WARNER_H_
+
+#include <memory>
+
+#include "base/atomicops.h"
+#include "base/base_export.h"
+#include "base/compiler_specific.h"
+#include "base/macros.h"
+
+// A helper class alongside macros to be used to verify assumptions about thread
+// safety of a class.
+//
+// Example: Queue implementation non thread-safe but still usable if clients
+//          are synchronized somehow.
+//
+//          In this case the macro DFAKE_SCOPED_LOCK has to be
+//          used, it checks that if a thread is inside the push/pop then
+//          noone else is still inside the pop/push
+//
+// class NonThreadSafeQueue {
+//  public:
+//   ...
+//   void push(int) { DFAKE_SCOPED_LOCK(push_pop_); ... }
+//   int pop() { DFAKE_SCOPED_LOCK(push_pop_); ... }
+//   ...
+//  private:
+//   DFAKE_MUTEX(push_pop_);
+// };
+//
+//
+// Example: Queue implementation non thread-safe but still usable if clients
+//          are synchronized somehow, it calls a method to "protect" from
+//          a "protected" method
+//
+//          In this case the macro DFAKE_SCOPED_RECURSIVE_LOCK
+//          has to be used, it checks that if a thread is inside the push/pop
+//          then noone else is still inside the pop/push
+//
+// class NonThreadSafeQueue {
+//  public:
+//   void push(int) {
+//     DFAKE_SCOPED_LOCK(push_pop_);
+//     ...
+//   }
+//   int pop() {
+//     DFAKE_SCOPED_RECURSIVE_LOCK(push_pop_);
+//     bar();
+//     ...
+//   }
+//   void bar() { DFAKE_SCOPED_RECURSIVE_LOCK(push_pop_); ... }
+//   ...
+//  private:
+//   DFAKE_MUTEX(push_pop_);
+// };
+//
+//
+// Example: Queue implementation not usable even if clients are synchronized,
+//          so only one thread in the class life cycle can use the two members
+//          push/pop.
+//
+//          In this case the macro DFAKE_SCOPED_LOCK_THREAD_LOCKED pins the
+//          specified
+//          critical section the first time a thread enters push or pop, from
+//          that time on only that thread is allowed to execute push or pop.
+//
+// class NonThreadSafeQueue {
+//  public:
+//   ...
+//   void push(int) { DFAKE_SCOPED_LOCK_THREAD_LOCKED(push_pop_); ... }
+//   int pop() { DFAKE_SCOPED_LOCK_THREAD_LOCKED(push_pop_); ... }
+//   ...
+//  private:
+//   DFAKE_MUTEX(push_pop_);
+// };
+//
+//
+// Example: Class that has to be contructed/destroyed on same thread, it has
+//          a "shareable" method (with external synchronization) and a not
+//          shareable method (even with external synchronization).
+//
+//          In this case 3 Critical sections have to be defined
+//
+// class ExoticClass {
+//  public:
+//   ExoticClass() { DFAKE_SCOPED_LOCK_THREAD_LOCKED(ctor_dtor_); ... }
+//   ~ExoticClass() { DFAKE_SCOPED_LOCK_THREAD_LOCKED(ctor_dtor_); ... }
+//
+//   void Shareable() { DFAKE_SCOPED_LOCK(shareable_section_); ... }
+//   void NotShareable() { DFAKE_SCOPED_LOCK_THREAD_LOCKED(ctor_dtor_); ... }
+//   ...
+//  private:
+//   DFAKE_MUTEX(ctor_dtor_);
+//   DFAKE_MUTEX(shareable_section_);
+// };
+
+
+#if !defined(NDEBUG)
+
+#define DFAKE_UNIQUE_VARIABLE_CONCAT(a, b) a##b
+// CONCAT1 provides extra level of indirection so that __LINE__ macro expands.
+#define DFAKE_UNIQUE_VARIABLE_CONCAT1(a, b) DFAKE_UNIQUE_VARIABLE_CONCAT(a, b)
+#define DFAKE_UNIQUE_VARIABLE_NAME(a) DFAKE_UNIQUE_VARIABLE_CONCAT1(a, __LINE__)
+
+// Defines a class member that acts like a mutex. It is used only as a
+// verification tool.
+#define DFAKE_MUTEX(obj) \
+     mutable base::ThreadCollisionWarner obj
+// Asserts the call is never called simultaneously in two threads. Used at
+// member function scope.
+#define DFAKE_SCOPED_LOCK(obj)                                         \
+  base::ThreadCollisionWarner::ScopedCheck DFAKE_UNIQUE_VARIABLE_NAME( \
+      s_check_)(&obj)
+// Asserts the call is never called simultaneously in two threads. Used at
+// member function scope. Same as DFAKE_SCOPED_LOCK but allows recursive locks.
+#define DFAKE_SCOPED_RECURSIVE_LOCK(obj)            \
+  base::ThreadCollisionWarner::ScopedRecursiveCheck \
+      DFAKE_UNIQUE_VARIABLE_NAME(sr_check)(&obj)
+// Asserts the code is always executed in the same thread.
+#define DFAKE_SCOPED_LOCK_THREAD_LOCKED(obj) \
+  base::ThreadCollisionWarner::Check DFAKE_UNIQUE_VARIABLE_NAME(check_)(&obj)
+
+#else
+
+#define DFAKE_MUTEX(obj) typedef void InternalFakeMutexType##obj
+#define DFAKE_SCOPED_LOCK(obj) ((void)0)
+#define DFAKE_SCOPED_RECURSIVE_LOCK(obj) ((void)0)
+#define DFAKE_SCOPED_LOCK_THREAD_LOCKED(obj) ((void)0)
+
+#endif
+
+namespace base {
+
+// The class ThreadCollisionWarner uses an Asserter to notify the collision
+// AsserterBase is the interfaces and DCheckAsserter is the default asserter
+// used. During the unit tests is used another class that doesn't "DCHECK"
+// in case of collision (check thread_collision_warner_unittests.cc)
+struct BASE_EXPORT AsserterBase {
+  virtual ~AsserterBase() = default;
+  virtual void warn() = 0;
+};
+
+struct BASE_EXPORT DCheckAsserter : public AsserterBase {
+  ~DCheckAsserter() override = default;
+  void warn() override;
+};
+
+class BASE_EXPORT ThreadCollisionWarner {
+ public:
+  // The parameter asserter is there only for test purpose
+  explicit ThreadCollisionWarner(AsserterBase* asserter = new DCheckAsserter())
+      : valid_thread_id_(0),
+        counter_(0),
+        asserter_(asserter) {}
+
+  ~ThreadCollisionWarner() {
+    delete asserter_;
+  }
+
+  // This class is meant to be used through the macro
+  // DFAKE_SCOPED_LOCK_THREAD_LOCKED
+  // it doesn't leave the critical section, as opposed to ScopedCheck,
+  // because the critical section being pinned is allowed to be used only
+  // from one thread
+  class BASE_EXPORT Check {
+   public:
+    explicit Check(ThreadCollisionWarner* warner)
+        : warner_(warner) {
+      warner_->EnterSelf();
+    }
+
+    ~Check() = default;
+
+   private:
+    ThreadCollisionWarner* warner_;
+
+    DISALLOW_COPY_AND_ASSIGN(Check);
+  };
+
+  // This class is meant to be used through the macro
+  // DFAKE_SCOPED_LOCK
+  class BASE_EXPORT ScopedCheck {
+   public:
+    explicit ScopedCheck(ThreadCollisionWarner* warner)
+        : warner_(warner) {
+      warner_->Enter();
+    }
+
+    ~ScopedCheck() {
+      warner_->Leave();
+    }
+
+   private:
+    ThreadCollisionWarner* warner_;
+
+    DISALLOW_COPY_AND_ASSIGN(ScopedCheck);
+  };
+
+  // This class is meant to be used through the macro
+  // DFAKE_SCOPED_RECURSIVE_LOCK
+  class BASE_EXPORT ScopedRecursiveCheck {
+   public:
+    explicit ScopedRecursiveCheck(ThreadCollisionWarner* warner)
+        : warner_(warner) {
+      warner_->EnterSelf();
+    }
+
+    ~ScopedRecursiveCheck() {
+      warner_->Leave();
+    }
+
+   private:
+    ThreadCollisionWarner* warner_;
+
+    DISALLOW_COPY_AND_ASSIGN(ScopedRecursiveCheck);
+  };
+
+ private:
+  // This method stores the current thread identifier and does a DCHECK
+  // if a another thread has already done it, it is safe if same thread
+  // calls this multiple time (recursion allowed).
+  void EnterSelf();
+
+  // Same as EnterSelf but recursion is not allowed.
+  void Enter();
+
+  // Removes the thread_id stored in order to allow other threads to
+  // call EnterSelf or Enter.
+  void Leave();
+
+  // This stores the thread id that is inside the critical section, if the
+  // value is 0 then no thread is inside.
+  volatile subtle::Atomic32 valid_thread_id_;
+
+  // Counter to trace how many time a critical section was "pinned"
+  // (when allowed) in order to unpin it when counter_ reaches 0.
+  volatile subtle::Atomic32 counter_;
+
+  // Here only for class unit tests purpose, during the test I need to not
+  // DCHECK but notify the collision with something else.
+  AsserterBase* asserter_;
+
+  DISALLOW_COPY_AND_ASSIGN(ThreadCollisionWarner);
+};
+
+}  // namespace base
+
+#endif  // BASE_THREADING_THREAD_COLLISION_WARNER_H_
diff --git a/security/sandbox/chromium/base/threading/thread_id_name_manager.cc b/security/sandbox/chromium/base/threading/thread_id_name_manager.cc
new file mode 100644
index 0000000000..ba2f9b41cb
--- /dev/null
+++ b/security/sandbox/chromium/base/threading/thread_id_name_manager.cc
@@ -0,0 +1,147 @@
+// 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/threading/thread_id_name_manager.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "base/logging.h"
+#include "base/memory/singleton.h"
+#include "base/no_destructor.h"
+#include "base/stl_util.h"
+#include "base/strings/string_util.h"
+#include "base/threading/thread_local.h"
+#include "base/trace_event/heap_profiler_allocation_context_tracker.h"
+
+namespace base {
+namespace {
+
+static const char kDefaultName[] = "";
+static std::string* g_default_name;
+
+ThreadLocalStorage::Slot& GetThreadNameTLS() {
+  static base::NoDestructor<base::ThreadLocalStorage::Slot> thread_name_tls;
+  return *thread_name_tls;
+}
+}
+
+ThreadIdNameManager::Observer::~Observer() = default;
+
+ThreadIdNameManager::ThreadIdNameManager()
+    : main_process_name_(nullptr), main_process_id_(kInvalidThreadId) {
+  g_default_name = new std::string(kDefaultName);
+
+  AutoLock locked(lock_);
+  name_to_interned_name_[kDefaultName] = g_default_name;
+}
+
+ThreadIdNameManager::~ThreadIdNameManager() = default;
+
+ThreadIdNameManager* ThreadIdNameManager::GetInstance() {
+  return Singleton<ThreadIdNameManager,
+      LeakySingletonTraits<ThreadIdNameManager> >::get();
+}
+
+const char* ThreadIdNameManager::GetDefaultInternedString() {
+  return g_default_name->c_str();
+}
+
+void ThreadIdNameManager::RegisterThread(PlatformThreadHandle::Handle handle,
+                                         PlatformThreadId id) {
+  AutoLock locked(lock_);
+  thread_id_to_handle_[id] = handle;
+  thread_handle_to_interned_name_[handle] =
+      name_to_interned_name_[kDefaultName];
+}
+
+void ThreadIdNameManager::AddObserver(Observer* obs) {
+  AutoLock locked(lock_);
+  DCHECK(!base::Contains(observers_, obs));
+  observers_.push_back(obs);
+}
+
+void ThreadIdNameManager::RemoveObserver(Observer* obs) {
+  AutoLock locked(lock_);
+  DCHECK(base::Contains(observers_, obs));
+  base::Erase(observers_, obs);
+}
+
+void ThreadIdNameManager::SetName(const std::string& name) {
+  PlatformThreadId id = PlatformThread::CurrentId();
+  std::string* leaked_str = nullptr;
+  {
+    AutoLock locked(lock_);
+    auto iter = name_to_interned_name_.find(name);
+    if (iter != name_to_interned_name_.end()) {
+      leaked_str = iter->second;
+    } else {
+      leaked_str = new std::string(name);
+      name_to_interned_name_[name] = leaked_str;
+    }
+
+    auto id_to_handle_iter = thread_id_to_handle_.find(id);
+
+    GetThreadNameTLS().Set(const_cast<char*>(leaked_str->c_str()));
+    for (Observer* obs : observers_)
+      obs->OnThreadNameChanged(leaked_str->c_str());
+
+    // The main thread of a process will not be created as a Thread object which
+    // means there is no PlatformThreadHandler registered.
+    if (id_to_handle_iter == thread_id_to_handle_.end()) {
+      main_process_name_ = leaked_str;
+      main_process_id_ = id;
+      return;
+    }
+    thread_handle_to_interned_name_[id_to_handle_iter->second] = leaked_str;
+  }
+
+  // Add the leaked thread name to heap profiler context tracker. The name added
+  // is valid for the lifetime of the process. AllocationContextTracker cannot
+  // call GetName(which holds a lock) during the first allocation because it can
+  // cause a deadlock when the first allocation happens in the
+  // ThreadIdNameManager itself when holding the lock.
+  trace_event::AllocationContextTracker::SetCurrentThreadName(
+      leaked_str->c_str());
+}
+
+const char* ThreadIdNameManager::GetName(PlatformThreadId id) {
+  AutoLock locked(lock_);
+
+  if (id == main_process_id_)
+    return main_process_name_->c_str();
+
+  auto id_to_handle_iter = thread_id_to_handle_.find(id);
+  if (id_to_handle_iter == thread_id_to_handle_.end())
+    return name_to_interned_name_[kDefaultName]->c_str();
+
+  auto handle_to_name_iter =
+      thread_handle_to_interned_name_.find(id_to_handle_iter->second);
+  return handle_to_name_iter->second->c_str();
+}
+
+const char* ThreadIdNameManager::GetNameForCurrentThread() {
+  const char* name = reinterpret_cast<const char*>(GetThreadNameTLS().Get());
+  return name ? name : kDefaultName;
+}
+
+void ThreadIdNameManager::RemoveName(PlatformThreadHandle::Handle handle,
+                                     PlatformThreadId id) {
+  AutoLock locked(lock_);
+  auto handle_to_name_iter = thread_handle_to_interned_name_.find(handle);
+
+  DCHECK(handle_to_name_iter != thread_handle_to_interned_name_.end());
+  thread_handle_to_interned_name_.erase(handle_to_name_iter);
+
+  auto id_to_handle_iter = thread_id_to_handle_.find(id);
+  DCHECK((id_to_handle_iter!= thread_id_to_handle_.end()));
+  // The given |id| may have been re-used by the system. Make sure the
+  // mapping points to the provided |handle| before removal.
+  if (id_to_handle_iter->second != handle)
+    return;
+
+  thread_id_to_handle_.erase(id_to_handle_iter);
+}
+
+}  // namespace base
diff --git a/security/sandbox/chromium/base/threading/thread_id_name_manager.h b/security/sandbox/chromium/base/threading/thread_id_name_manager.h
new file mode 100644
index 0000000000..e413da5d03
--- /dev/null
+++ b/security/sandbox/chromium/base/threading/thread_id_name_manager.h
@@ -0,0 +1,94 @@
+// 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.
+
+#ifndef BASE_THREADING_THREAD_ID_NAME_MANAGER_H_
+#define BASE_THREADING_THREAD_ID_NAME_MANAGER_H_
+
+#include <map>
+#include <string>
+#include <vector>
+
+#include "base/base_export.h"
+#include "base/callback.h"
+#include "base/macros.h"
+#include "base/observer_list.h"
+#include "base/synchronization/lock.h"
+#include "base/threading/platform_thread.h"
+
+namespace base {
+
+template <typename T>
+struct DefaultSingletonTraits;
+
+class BASE_EXPORT ThreadIdNameManager {
+ public:
+  static ThreadIdNameManager* GetInstance();
+
+  static const char* GetDefaultInternedString();
+
+  class BASE_EXPORT Observer {
+   public:
+    virtual ~Observer();
+
+    // Called on the thread whose name is changing, immediately after the name
+    // is set. |name| is a pointer to a C string that is guaranteed to remain
+    // valid for the duration of the process.
+    //
+    // NOTE: Will be called while ThreadIdNameManager's lock is held, so don't
+    // call back into it.
+    virtual void OnThreadNameChanged(const char* name) = 0;
+  };
+
+  // Register the mapping between a thread |id| and |handle|.
+  void RegisterThread(PlatformThreadHandle::Handle handle, PlatformThreadId id);
+
+  void AddObserver(Observer*);
+  void RemoveObserver(Observer*);
+
+  // Set the name for the current thread.
+  void SetName(const std::string& name);
+
+  // Get the name for the given id.
+  const char* GetName(PlatformThreadId id);
+
+  // Unlike |GetName|, this method using TLS and avoids touching |lock_|.
+  const char* GetNameForCurrentThread();
+
+  // Remove the name for the given id.
+  void RemoveName(PlatformThreadHandle::Handle handle, PlatformThreadId id);
+
+ private:
+  friend struct DefaultSingletonTraits<ThreadIdNameManager>;
+
+  typedef std::map<PlatformThreadId, PlatformThreadHandle::Handle>
+      ThreadIdToHandleMap;
+  typedef std::map<PlatformThreadHandle::Handle, std::string*>
+      ThreadHandleToInternedNameMap;
+  typedef std::map<std::string, std::string*> NameToInternedNameMap;
+
+  ThreadIdNameManager();
+  ~ThreadIdNameManager();
+
+  // lock_ protects the name_to_interned_name_, thread_id_to_handle_ and
+  // thread_handle_to_interned_name_ maps.
+  Lock lock_;
+
+  NameToInternedNameMap name_to_interned_name_;
+  ThreadIdToHandleMap thread_id_to_handle_;
+  ThreadHandleToInternedNameMap thread_handle_to_interned_name_;
+
+  // Treat the main process specially as there is no PlatformThreadHandle.
+  std::string* main_process_name_;
+  PlatformThreadId main_process_id_;
+
+  // There's no point using a base::ObserverList behind a lock, so we just use
+  // an std::vector instead.
+  std::vector<Observer*> observers_;
+
+  DISALLOW_COPY_AND_ASSIGN(ThreadIdNameManager);
+};
+
+}  // namespace base
+
+#endif  // BASE_THREADING_THREAD_ID_NAME_MANAGER_H_
diff --git a/security/sandbox/chromium/base/threading/thread_local.h b/security/sandbox/chromium/base/threading/thread_local.h
new file mode 100644
index 0000000000..f9762050b6
--- /dev/null
+++ b/security/sandbox/chromium/base/threading/thread_local.h
@@ -0,0 +1,136 @@
+// Copyright (c) 2011 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.
+
+// WARNING: Thread local storage is a bit tricky to get right. Please make sure
+// that this is really the proper solution for what you're trying to achieve.
+// Don't prematurely optimize, most likely you can just use a Lock.
+//
+// These classes implement a wrapper around ThreadLocalStorage::Slot. On
+// construction, they will allocate a TLS slot, and free the TLS slot on
+// destruction. No memory management (creation or destruction) is handled. This
+// means for uses of ThreadLocalPointer, you must correctly manage the memory
+// yourself, these classes will not destroy the pointer for you. There are no
+// at-thread-exit actions taken by these classes.
+//
+// ThreadLocalPointer<Type> wraps a Type*. It performs no creation or
+// destruction, so memory management must be handled elsewhere. The first call
+// to Get() on a thread will return NULL. You can update the pointer with a call
+// to Set().
+//
+// ThreadLocalBoolean wraps a bool. It will default to false if it has never
+// been set otherwise with Set().
+//
+// Thread Safety: An instance of ThreadLocalStorage is completely thread safe
+// once it has been created. If you want to dynamically create an instance, you
+// must of course properly deal with safety and race conditions.
+//
+// In Android, the system TLS is limited.
+//
+// Example usage:
+//   // My class is logically attached to a single thread. We cache a pointer
+//   // on the thread it was created on, so we can implement current().
+//   MyClass::MyClass() {
+//     DCHECK(Singleton<ThreadLocalPointer<MyClass> >::get()->Get() == NULL);
+//     Singleton<ThreadLocalPointer<MyClass> >::get()->Set(this);
+//   }
+//
+//   MyClass::~MyClass() {
+//     DCHECK(Singleton<ThreadLocalPointer<MyClass> >::get()->Get() != NULL);
+//     Singleton<ThreadLocalPointer<MyClass> >::get()->Set(NULL);
+//   }
+//
+//   // Return the current MyClass associated with the calling thread, can be
+//   // NULL if there isn't a MyClass associated.
+//   MyClass* MyClass::current() {
+//     return Singleton<ThreadLocalPointer<MyClass> >::get()->Get();
+//   }
+
+#ifndef BASE_THREADING_THREAD_LOCAL_H_
+#define BASE_THREADING_THREAD_LOCAL_H_
+
+#include <memory>
+
+#include "base/logging.h"
+#include "base/macros.h"
+#include "base/threading/thread_local_internal.h"
+#include "base/threading/thread_local_storage.h"
+
+namespace base {
+
+template <typename T>
+class ThreadLocalPointer {
+ public:
+  ThreadLocalPointer() = default;
+  ~ThreadLocalPointer() = default;
+
+  T* Get() const { return static_cast<T*>(slot_.Get()); }
+
+  void Set(T* ptr) {
+    slot_.Set(const_cast<void*>(static_cast<const void*>(ptr)));
+  }
+
+ private:
+  ThreadLocalStorage::Slot slot_;
+
+  DISALLOW_COPY_AND_ASSIGN(ThreadLocalPointer<T>);
+};
+
+// A ThreadLocalOwnedPointer<T> is like a ThreadLocalPointer<T> except that
+// pointers handed to it are owned and automatically deleted during their
+// associated thread's exit phase (or when replaced if Set() is invoked multiple
+// times on the same thread).
+// The ThreadLocalOwnedPointer instance itself can only be destroyed when no
+// threads, other than the one it is destroyed on, have remaining state set in
+// it. Typically this means that ThreadLocalOwnedPointer instances are held in
+// static storage or at the very least only recycled in the single-threaded
+// phase between tests in the same process.
+#if DCHECK_IS_ON()
+template <typename T>
+using ThreadLocalOwnedPointer = internal::CheckedThreadLocalOwnedPointer<T>;
+#else   // DCHECK_IS_ON()
+template <typename T>
+class ThreadLocalOwnedPointer {
+ public:
+  ThreadLocalOwnedPointer() = default;
+
+  ~ThreadLocalOwnedPointer() {
+    // Assume that this thread is the only one with potential state left. This
+    // is verified in ~CheckedThreadLocalOwnedPointer().
+    Set(nullptr);
+  }
+
+  T* Get() const { return static_cast<T*>(slot_.Get()); }
+
+  void Set(std::unique_ptr<T> ptr) {
+    delete Get();
+    slot_.Set(const_cast<void*>(static_cast<const void*>(ptr.release())));
+  }
+
+ private:
+  static void DeleteTlsPtr(void* ptr) { delete static_cast<T*>(ptr); }
+
+  ThreadLocalStorage::Slot slot_{&DeleteTlsPtr};
+
+  DISALLOW_COPY_AND_ASSIGN(ThreadLocalOwnedPointer<T>);
+};
+#endif  // DCHECK_IS_ON()
+
+class ThreadLocalBoolean {
+ public:
+  ThreadLocalBoolean() = default;
+  ~ThreadLocalBoolean() = default;
+
+  bool Get() const { return tlp_.Get() != nullptr; }
+
+  void Set(bool val) { tlp_.Set(val ? this : nullptr); }
+
+ private:
+  ThreadLocalPointer<void> tlp_;
+
+  DISALLOW_COPY_AND_ASSIGN(ThreadLocalBoolean);
+};
+
+}  // namespace base
+
+#endif  // BASE_THREADING_THREAD_LOCAL_H_
diff --git a/security/sandbox/chromium/base/threading/thread_local_internal.h b/security/sandbox/chromium/base/threading/thread_local_internal.h
new file mode 100644
index 0000000000..6f7fdc9768
--- /dev/null
+++ b/security/sandbox/chromium/base/threading/thread_local_internal.h
@@ -0,0 +1,80 @@
+// Copyright 2019 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.
+
+#ifndef BASE_THREADING_THREAD_LOCAL_INTERNAL_H_
+#define BASE_THREADING_THREAD_LOCAL_INTERNAL_H_
+
+#if DCHECK_IS_ON()
+
+#include <atomic>
+#include <memory>
+
+#include "base/macros.h"
+#include "base/threading/thread_local_storage.h"
+
+namespace base {
+namespace internal {
+
+// A version of ThreadLocalOwnedPointer which verifies that it's only destroyed
+// when no threads, other than the one it is destroyed on, have remaining state
+// set in it. A ThreadLocalOwnedPointer instance being destroyed too early would
+// result in leaks per unregistering the TLS slot (and thus the DeleteTlsPtr
+// hook).
+template <typename T>
+class CheckedThreadLocalOwnedPointer {
+ public:
+  CheckedThreadLocalOwnedPointer() = default;
+
+  ~CheckedThreadLocalOwnedPointer() {
+    Set(nullptr);
+
+    DCHECK_EQ(num_assigned_threads_.load(std::memory_order_relaxed), 0)
+        << "Memory leak: Must join all threads or release all associated "
+           "thread-local slots before ~ThreadLocalOwnedPointer";
+  }
+
+  T* Get() const {
+    PtrTracker* const ptr_tracker = static_cast<PtrTracker*>(slot_.Get());
+    return ptr_tracker ? ptr_tracker->ptr_.get() : nullptr;
+  }
+
+  void Set(std::unique_ptr<T> ptr) {
+    delete static_cast<PtrTracker*>(slot_.Get());
+    if (ptr)
+      slot_.Set(new PtrTracker(this, std::move(ptr)));
+    else
+      slot_.Set(nullptr);
+  }
+
+ private:
+  struct PtrTracker {
+   public:
+    PtrTracker(CheckedThreadLocalOwnedPointer<T>* outer, std::unique_ptr<T> ptr)
+        : outer_(outer), ptr_(std::move(ptr)) {
+      outer_->num_assigned_threads_.fetch_add(1, std::memory_order_relaxed);
+    }
+
+    ~PtrTracker() {
+      outer_->num_assigned_threads_.fetch_sub(1, std::memory_order_relaxed);
+    }
+
+    CheckedThreadLocalOwnedPointer<T>* const outer_;
+    const std::unique_ptr<T> ptr_;
+  };
+
+  static void DeleteTlsPtr(void* ptr) { delete static_cast<PtrTracker*>(ptr); }
+
+  ThreadLocalStorage::Slot slot_{&DeleteTlsPtr};
+
+  std::atomic_int num_assigned_threads_{0};
+
+  DISALLOW_COPY_AND_ASSIGN(CheckedThreadLocalOwnedPointer<T>);
+};
+
+}  // namespace internal
+}  // namespace base
+
+#endif  // DCHECK_IS_ON()
+
+#endif  // BASE_THREADING_THREAD_LOCAL_INTERNAL_H_
diff --git a/security/sandbox/chromium/base/threading/thread_local_storage.cc b/security/sandbox/chromium/base/threading/thread_local_storage.cc
new file mode 100644
index 0000000000..204f34c272
--- /dev/null
+++ b/security/sandbox/chromium/base/threading/thread_local_storage.cc
@@ -0,0 +1,461 @@
+// Copyright 2014 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/threading/thread_local_storage.h"
+
+#include "base/atomicops.h"
+#include "base/compiler_specific.h"
+#include "base/logging.h"
+#include "base/no_destructor.h"
+#include "base/synchronization/lock.h"
+#include "build/build_config.h"
+
+using base::internal::PlatformThreadLocalStorage;
+
+// Chrome Thread Local Storage (TLS)
+//
+// This TLS system allows Chrome to use a single OS level TLS slot process-wide,
+// and allows us to control the slot limits instead of being at the mercy of the
+// platform. To do this, Chrome TLS replicates an array commonly found in the OS
+// thread metadata.
+//
+// Overview:
+//
+// OS TLS Slots       Per-Thread                 Per-Process Global
+//     ...
+//     []             Chrome TLS Array           Chrome TLS Metadata
+//     [] ----------> [][][][][ ][][][][]        [][][][][ ][][][][]
+//     []                      |                          |
+//     ...                     V                          V
+//                      Metadata Version           Slot Information
+//                         Your Data!
+//
+// Using a single OS TLS slot, Chrome TLS allocates an array on demand for the
+// lifetime of each thread that requests Chrome TLS data. Each per-thread TLS
+// array matches the length of the per-process global metadata array.
+//
+// A per-process global TLS metadata array tracks information about each item in
+// the per-thread array:
+//   * Status: Tracks if the slot is allocated or free to assign.
+//   * Destructor: An optional destructor to call on thread destruction for that
+//                 specific slot.
+//   * Version: Tracks the current version of the TLS slot. Each TLS slot
+//              allocation is associated with a unique version number.
+//
+//              Most OS TLS APIs guarantee that a newly allocated TLS slot is
+//              initialized to 0 for all threads. The Chrome TLS system provides
+//              this guarantee by tracking the version for each TLS slot here
+//              on each per-thread Chrome TLS array entry. Threads that access
+//              a slot with a mismatched version will receive 0 as their value.
+//              The metadata version is incremented when the client frees a
+//              slot. The per-thread metadata version is updated when a client
+//              writes to the slot. This scheme allows for constant time
+//              invalidation and avoids the need to iterate through each Chrome
+//              TLS array to mark the slot as zero.
+//
+// Just like an OS TLS API, clients of the Chrome TLS are responsible for
+// managing any necessary lifetime of the data in their slots. The only
+// convenience provided is automatic destruction when a thread ends. If a client
+// frees a slot, that client is responsible for destroying the data in the slot.
+
+namespace {
+// In order to make TLS destructors work, we need to keep around a function
+// pointer to the destructor for each slot. We keep this array of pointers in a
+// global (static) array.
+// We use the single OS-level TLS slot (giving us one pointer per thread) to
+// hold a pointer to a per-thread array (table) of slots that we allocate to
+// Chromium consumers.
+
+// g_native_tls_key is the one native TLS that we use. It stores our table.
+base::subtle::Atomic32 g_native_tls_key =
+    PlatformThreadLocalStorage::TLS_KEY_OUT_OF_INDEXES;
+
+// The OS TLS slot has the following states. The TLS slot's lower 2 bits contain
+// the state, the upper bits the TlsVectorEntry*.
+//   * kUninitialized: Any call to Slot::Get()/Set() will create the base
+//     per-thread TLS state. kUninitialized must be null.
+//   * kInUse: value has been created and is in use.
+//   * kDestroying: Set when the thread is exiting prior to deleting any of the
+//     values stored in the TlsVectorEntry*. This state is necessary so that
+//     sequence/task checks won't be done while in the process of deleting the
+//     tls entries (see comments in SequenceCheckerImpl for more details).
+//   * kDestroyed: All of the values in the vector have been deallocated and
+//     the TlsVectorEntry has been deleted.
+//
+// Final States:
+//   * Windows: kDestroyed. Windows does not iterate through the OS TLS to clean
+//     up the values.
+//   * POSIX: kUninitialized. POSIX iterates through TLS until all slots contain
+//     nullptr.
+//
+// More details on this design:
+//   We need some type of thread-local state to indicate that the TLS system has
+//   been destroyed. To do so, we leverage the multi-pass nature of destruction
+//   of pthread_key.
+//
+//    a) After destruction of TLS system, we set the pthread_key to a sentinel
+//       kDestroyed.
+//    b) All calls to Slot::Get() DCHECK that the state is not kDestroyed, and
+//       any system which might potentially invoke Slot::Get() after destruction
+//       of TLS must check ThreadLocalStorage::ThreadIsBeingDestroyed().
+//    c) After a full pass of the pthread_keys, on the next invocation of
+//       ConstructTlsVector(), we'll then set the key to nullptr.
+//    d) At this stage, the TLS system is back in its uninitialized state.
+//    e) If in the second pass of destruction of pthread_keys something were to
+//       re-initialize TLS [this should never happen! Since the only code which
+//       uses Chrome TLS is Chrome controlled, we should really be striving for
+//       single-pass destruction], then TLS will be re-initialized and then go
+//       through the 2-pass destruction system again. Everything should just
+//       work (TM).
+
+// The state of the tls-entry.
+enum class TlsVectorState {
+  kUninitialized = 0,
+
+  // In the process of destroying the entries in the vector.
+  kDestroying,
+
+  // All of the entries and the vector has been destroyed.
+  kDestroyed,
+
+  // The vector has been initialized and is in use.
+  kInUse,
+
+  kMaxValue = kInUse
+};
+
+// Bit-mask used to store TlsVectorState.
+constexpr uintptr_t kVectorStateBitMask = 3;
+static_assert(static_cast<int>(TlsVectorState::kMaxValue) <=
+                  kVectorStateBitMask,
+              "number of states must fit in header");
+static_assert(static_cast<int>(TlsVectorState::kUninitialized) == 0,
+              "kUninitialized must be null");
+
+// The maximum number of slots in our thread local storage stack.
+constexpr int kThreadLocalStorageSize = 256;
+
+enum TlsStatus {
+  FREE,
+  IN_USE,
+};
+
+struct TlsMetadata {
+  TlsStatus status;
+  base::ThreadLocalStorage::TLSDestructorFunc destructor;
+  // Incremented every time a slot is reused. Used to detect reuse of slots.
+  uint32_t version;
+};
+
+struct TlsVectorEntry {
+  void* data;
+  uint32_t version;
+};
+
+// This lock isn't needed until after we've constructed the per-thread TLS
+// vector, so it's safe to use.
+base::Lock* GetTLSMetadataLock() {
+  static auto* lock = new base::Lock();
+  return lock;
+}
+TlsMetadata g_tls_metadata[kThreadLocalStorageSize];
+size_t g_last_assigned_slot = 0;
+
+// The maximum number of times to try to clear slots by calling destructors.
+// Use pthread naming convention for clarity.
+constexpr int kMaxDestructorIterations = kThreadLocalStorageSize;
+
+// Sets the value and state of the vector.
+void SetTlsVectorValue(PlatformThreadLocalStorage::TLSKey key,
+                       TlsVectorEntry* tls_data,
+                       TlsVectorState state) {
+  DCHECK(tls_data || (state == TlsVectorState::kUninitialized) ||
+         (state == TlsVectorState::kDestroyed));
+  PlatformThreadLocalStorage::SetTLSValue(
+      key, reinterpret_cast<void*>(reinterpret_cast<uintptr_t>(tls_data) |
+                                   static_cast<uintptr_t>(state)));
+}
+
+// Returns the tls vector and current state from the raw tls value.
+TlsVectorState GetTlsVectorStateAndValue(void* tls_value,
+                                         TlsVectorEntry** entry = nullptr) {
+  if (entry) {
+    *entry = reinterpret_cast<TlsVectorEntry*>(
+        reinterpret_cast<uintptr_t>(tls_value) & ~kVectorStateBitMask);
+  }
+  return static_cast<TlsVectorState>(reinterpret_cast<uintptr_t>(tls_value) &
+                                     kVectorStateBitMask);
+}
+
+// Returns the tls vector and state using the tls key.
+TlsVectorState GetTlsVectorStateAndValue(PlatformThreadLocalStorage::TLSKey key,
+                                         TlsVectorEntry** entry = nullptr) {
+  return GetTlsVectorStateAndValue(PlatformThreadLocalStorage::GetTLSValue(key),
+                                   entry);
+}
+
+// This function is called to initialize our entire Chromium TLS system.
+// It may be called very early, and we need to complete most all of the setup
+// (initialization) before calling *any* memory allocator functions, which may
+// recursively depend on this initialization.
+// As a result, we use Atomics, and avoid anything (like a singleton) that might
+// require memory allocations.
+TlsVectorEntry* ConstructTlsVector() {
+  PlatformThreadLocalStorage::TLSKey key =
+      base::subtle::NoBarrier_Load(&g_native_tls_key);
+  if (key == PlatformThreadLocalStorage::TLS_KEY_OUT_OF_INDEXES) {
+    CHECK(PlatformThreadLocalStorage::AllocTLS(&key));
+
+    // The TLS_KEY_OUT_OF_INDEXES is used to find out whether the key is set or
+    // not in NoBarrier_CompareAndSwap, but Posix doesn't have invalid key, we
+    // define an almost impossible value be it.
+    // If we really get TLS_KEY_OUT_OF_INDEXES as value of key, just alloc
+    // another TLS slot.
+    if (key == PlatformThreadLocalStorage::TLS_KEY_OUT_OF_INDEXES) {
+      PlatformThreadLocalStorage::TLSKey tmp = key;
+      CHECK(PlatformThreadLocalStorage::AllocTLS(&key) &&
+            key != PlatformThreadLocalStorage::TLS_KEY_OUT_OF_INDEXES);
+      PlatformThreadLocalStorage::FreeTLS(tmp);
+    }
+    // Atomically test-and-set the tls_key. If the key is
+    // TLS_KEY_OUT_OF_INDEXES, go ahead and set it. Otherwise, do nothing, as
+    // another thread already did our dirty work.
+    if (PlatformThreadLocalStorage::TLS_KEY_OUT_OF_INDEXES !=
+        static_cast<PlatformThreadLocalStorage::TLSKey>(
+            base::subtle::NoBarrier_CompareAndSwap(
+                &g_native_tls_key,
+                PlatformThreadLocalStorage::TLS_KEY_OUT_OF_INDEXES, key))) {
+      // We've been shortcut. Another thread replaced g_native_tls_key first so
+      // we need to destroy our index and use the one the other thread got
+      // first.
+      PlatformThreadLocalStorage::FreeTLS(key);
+      key = base::subtle::NoBarrier_Load(&g_native_tls_key);
+    }
+  }
+  CHECK_EQ(GetTlsVectorStateAndValue(key), TlsVectorState::kUninitialized);
+
+  // Some allocators, such as TCMalloc, make use of thread local storage. As a
+  // result, any attempt to call new (or malloc) will lazily cause such a system
+  // to initialize, which will include registering for a TLS key. If we are not
+  // careful here, then that request to create a key will call new back, and
+  // we'll have an infinite loop. We avoid that as follows: Use a stack
+  // allocated vector, so that we don't have dependence on our allocator until
+  // our service is in place. (i.e., don't even call new until after we're
+  // setup)
+  TlsVectorEntry stack_allocated_tls_data[kThreadLocalStorageSize];
+  memset(stack_allocated_tls_data, 0, sizeof(stack_allocated_tls_data));
+  // Ensure that any rentrant calls change the temp version.
+  SetTlsVectorValue(key, stack_allocated_tls_data, TlsVectorState::kInUse);
+
+  // Allocate an array to store our data.
+  TlsVectorEntry* tls_data = new TlsVectorEntry[kThreadLocalStorageSize];
+  memcpy(tls_data, stack_allocated_tls_data, sizeof(stack_allocated_tls_data));
+  SetTlsVectorValue(key, tls_data, TlsVectorState::kInUse);
+  return tls_data;
+}
+
+void OnThreadExitInternal(TlsVectorEntry* tls_data) {
+  DCHECK(tls_data);
+  // Some allocators, such as TCMalloc, use TLS. As a result, when a thread
+  // terminates, one of the destructor calls we make may be to shut down an
+  // allocator. We have to be careful that after we've shutdown all of the known
+  // destructors (perchance including an allocator), that we don't call the
+  // allocator and cause it to resurrect itself (with no possibly destructor
+  // call to follow). We handle this problem as follows: Switch to using a stack
+  // allocated vector, so that we don't have dependence on our allocator after
+  // we have called all g_tls_metadata destructors. (i.e., don't even call
+  // delete[] after we're done with destructors.)
+  TlsVectorEntry stack_allocated_tls_data[kThreadLocalStorageSize];
+  memcpy(stack_allocated_tls_data, tls_data, sizeof(stack_allocated_tls_data));
+  // Ensure that any re-entrant calls change the temp version.
+  PlatformThreadLocalStorage::TLSKey key =
+      base::subtle::NoBarrier_Load(&g_native_tls_key);
+  SetTlsVectorValue(key, stack_allocated_tls_data, TlsVectorState::kDestroying);
+  delete[] tls_data;  // Our last dependence on an allocator.
+
+  // Snapshot the TLS Metadata so we don't have to lock on every access.
+  TlsMetadata tls_metadata[kThreadLocalStorageSize];
+  {
+    base::AutoLock auto_lock(*GetTLSMetadataLock());
+    memcpy(tls_metadata, g_tls_metadata, sizeof(g_tls_metadata));
+  }
+
+  int remaining_attempts = kMaxDestructorIterations;
+  bool need_to_scan_destructors = true;
+  while (need_to_scan_destructors) {
+    need_to_scan_destructors = false;
+    // Try to destroy the first-created-slot (which is slot 1) in our last
+    // destructor call. That user was able to function, and define a slot with
+    // no other services running, so perhaps it is a basic service (like an
+    // allocator) and should also be destroyed last. If we get the order wrong,
+    // then we'll iterate several more times, so it is really not that critical
+    // (but it might help).
+    for (int slot = 0; slot < kThreadLocalStorageSize; ++slot) {
+      void* tls_value = stack_allocated_tls_data[slot].data;
+      if (!tls_value || tls_metadata[slot].status == TlsStatus::FREE ||
+          stack_allocated_tls_data[slot].version != tls_metadata[slot].version)
+        continue;
+
+      base::ThreadLocalStorage::TLSDestructorFunc destructor =
+          tls_metadata[slot].destructor;
+      if (!destructor)
+        continue;
+      stack_allocated_tls_data[slot].data = nullptr;  // pre-clear the slot.
+      destructor(tls_value);
+      // Any destructor might have called a different service, which then set a
+      // different slot to a non-null value. Hence we need to check the whole
+      // vector again. This is a pthread standard.
+      need_to_scan_destructors = true;
+    }
+    if (--remaining_attempts <= 0) {
+      NOTREACHED();  // Destructors might not have been called.
+      break;
+    }
+  }
+
+  // Remove our stack allocated vector.
+  SetTlsVectorValue(key, nullptr, TlsVectorState::kDestroyed);
+}
+
+}  // namespace
+
+namespace base {
+
+namespace internal {
+
+#if defined(OS_WIN)
+void PlatformThreadLocalStorage::OnThreadExit() {
+  PlatformThreadLocalStorage::TLSKey key =
+      base::subtle::NoBarrier_Load(&g_native_tls_key);
+  if (key == PlatformThreadLocalStorage::TLS_KEY_OUT_OF_INDEXES)
+    return;
+  TlsVectorEntry* tls_vector = nullptr;
+  const TlsVectorState state = GetTlsVectorStateAndValue(key, &tls_vector);
+
+  // On Windows, thread destruction callbacks are only invoked once per module,
+  // so there should be no way that this could be invoked twice.
+  DCHECK_NE(state, TlsVectorState::kDestroyed);
+
+  // Maybe we have never initialized TLS for this thread.
+  if (state == TlsVectorState::kUninitialized)
+    return;
+  OnThreadExitInternal(tls_vector);
+}
+#elif defined(OS_POSIX) || defined(OS_FUCHSIA)
+void PlatformThreadLocalStorage::OnThreadExit(void* value) {
+  // On posix this function may be called twice. The first pass calls dtors and
+  // sets state to kDestroyed. The second pass sets kDestroyed to
+  // kUninitialized.
+  TlsVectorEntry* tls_vector = nullptr;
+  const TlsVectorState state = GetTlsVectorStateAndValue(value, &tls_vector);
+  if (state == TlsVectorState::kDestroyed) {
+    PlatformThreadLocalStorage::TLSKey key =
+        base::subtle::NoBarrier_Load(&g_native_tls_key);
+    SetTlsVectorValue(key, nullptr, TlsVectorState::kUninitialized);
+    return;
+  }
+
+  OnThreadExitInternal(tls_vector);
+}
+#endif  // defined(OS_WIN)
+
+}  // namespace internal
+
+// static
+bool ThreadLocalStorage::HasBeenDestroyed() {
+  PlatformThreadLocalStorage::TLSKey key =
+      base::subtle::NoBarrier_Load(&g_native_tls_key);
+  if (key == PlatformThreadLocalStorage::TLS_KEY_OUT_OF_INDEXES)
+    return false;
+  const TlsVectorState state = GetTlsVectorStateAndValue(key);
+  return state == TlsVectorState::kDestroying ||
+         state == TlsVectorState::kDestroyed;
+}
+
+void ThreadLocalStorage::Slot::Initialize(TLSDestructorFunc destructor) {
+  PlatformThreadLocalStorage::TLSKey key =
+      base::subtle::NoBarrier_Load(&g_native_tls_key);
+  if (key == PlatformThreadLocalStorage::TLS_KEY_OUT_OF_INDEXES ||
+      GetTlsVectorStateAndValue(key) == TlsVectorState::kUninitialized) {
+    ConstructTlsVector();
+  }
+
+  // Grab a new slot.
+  {
+    base::AutoLock auto_lock(*GetTLSMetadataLock());
+    for (int i = 0; i < kThreadLocalStorageSize; ++i) {
+      // Tracking the last assigned slot is an attempt to find the next
+      // available slot within one iteration. Under normal usage, slots remain
+      // in use for the lifetime of the process (otherwise before we reclaimed
+      // slots, we would have run out of slots). This makes it highly likely the
+      // next slot is going to be a free slot.
+      size_t slot_candidate =
+          (g_last_assigned_slot + 1 + i) % kThreadLocalStorageSize;
+      if (g_tls_metadata[slot_candidate].status == TlsStatus::FREE) {
+        g_tls_metadata[slot_candidate].status = TlsStatus::IN_USE;
+        g_tls_metadata[slot_candidate].destructor = destructor;
+        g_last_assigned_slot = slot_candidate;
+        DCHECK_EQ(kInvalidSlotValue, slot_);
+        slot_ = slot_candidate;
+        version_ = g_tls_metadata[slot_candidate].version;
+        break;
+      }
+    }
+  }
+  CHECK_NE(slot_, kInvalidSlotValue);
+  CHECK_LT(slot_, kThreadLocalStorageSize);
+}
+
+void ThreadLocalStorage::Slot::Free() {
+  DCHECK_NE(slot_, kInvalidSlotValue);
+  DCHECK_LT(slot_, kThreadLocalStorageSize);
+  {
+    base::AutoLock auto_lock(*GetTLSMetadataLock());
+    g_tls_metadata[slot_].status = TlsStatus::FREE;
+    g_tls_metadata[slot_].destructor = nullptr;
+    ++(g_tls_metadata[slot_].version);
+  }
+  slot_ = kInvalidSlotValue;
+}
+
+void* ThreadLocalStorage::Slot::Get() const {
+  TlsVectorEntry* tls_data = nullptr;
+  const TlsVectorState state = GetTlsVectorStateAndValue(
+      base::subtle::NoBarrier_Load(&g_native_tls_key), &tls_data);
+  DCHECK_NE(state, TlsVectorState::kDestroyed);
+  if (!tls_data)
+    return nullptr;
+  DCHECK_NE(slot_, kInvalidSlotValue);
+  DCHECK_LT(slot_, kThreadLocalStorageSize);
+  // Version mismatches means this slot was previously freed.
+  if (tls_data[slot_].version != version_)
+    return nullptr;
+  return tls_data[slot_].data;
+}
+
+void ThreadLocalStorage::Slot::Set(void* value) {
+  TlsVectorEntry* tls_data = nullptr;
+  const TlsVectorState state = GetTlsVectorStateAndValue(
+      base::subtle::NoBarrier_Load(&g_native_tls_key), &tls_data);
+  DCHECK_NE(state, TlsVectorState::kDestroyed);
+  if (!tls_data) {
+    if (!value)
+      return;
+    tls_data = ConstructTlsVector();
+  }
+  DCHECK_NE(slot_, kInvalidSlotValue);
+  DCHECK_LT(slot_, kThreadLocalStorageSize);
+  tls_data[slot_].data = value;
+  tls_data[slot_].version = version_;
+}
+
+ThreadLocalStorage::Slot::Slot(TLSDestructorFunc destructor) {
+  Initialize(destructor);
+}
+
+ThreadLocalStorage::Slot::~Slot() {
+  Free();
+}
+
+}  // namespace base
diff --git a/security/sandbox/chromium/base/threading/thread_local_storage.h b/security/sandbox/chromium/base/threading/thread_local_storage.h
new file mode 100644
index 0000000000..73b845ef56
--- /dev/null
+++ b/security/sandbox/chromium/base/threading/thread_local_storage.h
@@ -0,0 +1,175 @@
+// 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.
+
+#ifndef BASE_THREADING_THREAD_LOCAL_STORAGE_H_
+#define BASE_THREADING_THREAD_LOCAL_STORAGE_H_
+
+#include <stdint.h>
+
+#include "base/atomicops.h"
+#include "base/base_export.h"
+#include "base/macros.h"
+#include "build/build_config.h"
+
+#if defined(OS_WIN)
+#include "base/win/windows_types.h"
+#elif defined(OS_POSIX) || defined(OS_FUCHSIA)
+#include <pthread.h>
+#endif
+
+namespace ui {
+class TLSDestructionCheckerForX11;
+}
+
+namespace base {
+
+class SamplingHeapProfiler;
+
+namespace debug {
+class GlobalActivityTracker;
+}  // namespace debug
+
+namespace trace_event {
+class MallocDumpProvider;
+}  // namespace trace_event
+
+namespace internal {
+
+class ThreadLocalStorageTestInternal;
+
+// WARNING: You should *NOT* use this class directly.
+// PlatformThreadLocalStorage is a low-level abstraction of the OS's TLS
+// interface. Instead, you should use one of the following:
+// * ThreadLocalBoolean (from thread_local.h) for booleans.
+// * ThreadLocalPointer (from thread_local.h) for pointers.
+// * ThreadLocalStorage::StaticSlot/Slot for more direct control of the slot.
+class BASE_EXPORT PlatformThreadLocalStorage {
+ public:
+
+#if defined(OS_WIN)
+  typedef unsigned long TLSKey;
+  enum : unsigned { TLS_KEY_OUT_OF_INDEXES = TLS_OUT_OF_INDEXES };
+#elif defined(OS_POSIX) || defined(OS_FUCHSIA)
+  typedef pthread_key_t TLSKey;
+  // The following is a "reserved key" which is used in our generic Chromium
+  // ThreadLocalStorage implementation.  We expect that an OS will not return
+  // such a key, but if it is returned (i.e., the OS tries to allocate it) we
+  // will just request another key.
+  enum { TLS_KEY_OUT_OF_INDEXES = 0x7FFFFFFF };
+#endif
+
+  // The following methods need to be supported on each OS platform, so that
+  // the Chromium ThreadLocalStore functionality can be constructed.
+  // Chromium will use these methods to acquire a single OS slot, and then use
+  // that to support a much larger number of Chromium slots (independent of the
+  // OS restrictions).
+  // The following returns true if it successfully is able to return an OS
+  // key in |key|.
+  static bool AllocTLS(TLSKey* key);
+  // Note: FreeTLS() doesn't have to be called, it is fine with this leak, OS
+  // might not reuse released slot, you might just reset the TLS value with
+  // SetTLSValue().
+  static void FreeTLS(TLSKey key);
+  static void SetTLSValue(TLSKey key, void* value);
+  static void* GetTLSValue(TLSKey key) {
+#if defined(OS_WIN)
+    return TlsGetValue(key);
+#elif defined(OS_POSIX) || defined(OS_FUCHSIA)
+    return pthread_getspecific(key);
+#endif
+  }
+
+  // Each platform (OS implementation) is required to call this method on each
+  // terminating thread when the thread is about to terminate.  This method
+  // will then call all registered destructors for slots in Chromium
+  // ThreadLocalStorage, until there are no slot values remaining as having
+  // been set on this thread.
+  // Destructors may end up being called multiple times on a terminating
+  // thread, as other destructors may re-set slots that were previously
+  // destroyed.
+#if defined(OS_WIN)
+  // Since Windows which doesn't support TLS destructor, the implementation
+  // should use GetTLSValue() to retrieve the value of TLS slot.
+  static void OnThreadExit();
+#elif defined(OS_POSIX) || defined(OS_FUCHSIA)
+  // |Value| is the data stored in TLS slot, The implementation can't use
+  // GetTLSValue() to retrieve the value of slot as it has already been reset
+  // in Posix.
+  static void OnThreadExit(void* value);
+#endif
+};
+
+}  // namespace internal
+
+// Wrapper for thread local storage.  This class doesn't do much except provide
+// an API for portability.
+class BASE_EXPORT ThreadLocalStorage {
+ public:
+  // Prototype for the TLS destructor function, which can be optionally used to
+  // cleanup thread local storage on thread exit.  'value' is the data that is
+  // stored in thread local storage.
+  typedef void (*TLSDestructorFunc)(void* value);
+
+  // A key representing one value stored in TLS. Use as a class member or a
+  // local variable. If you need a static storage duration variable, use the
+  // following pattern with a NoDestructor<Slot>:
+  // void MyDestructorFunc(void* value);
+  // ThreadLocalStorage::Slot& ImportantContentTLS() {
+  //   static NoDestructor<ThreadLocalStorage::Slot> important_content_tls(
+  //       &MyDestructorFunc);
+  //   return *important_content_tls;
+  // }
+  class BASE_EXPORT Slot final {
+   public:
+    // |destructor| is a pointer to a function to perform per-thread cleanup of
+    // this object.  If set to nullptr, no cleanup is done for this TLS slot.
+    explicit Slot(TLSDestructorFunc destructor = nullptr);
+    // If a destructor was set for this slot, removes the destructor so that
+    // remaining threads exiting will not free data.
+    ~Slot();
+
+    // Get the thread-local value stored in slot 'slot'.
+    // Values are guaranteed to initially be zero.
+    void* Get() const;
+
+    // Set the thread-local value stored in slot 'slot' to
+    // value 'value'.
+    void Set(void* value);
+
+   private:
+    void Initialize(TLSDestructorFunc destructor);
+    void Free();
+
+    static constexpr int kInvalidSlotValue = -1;
+    int slot_ = kInvalidSlotValue;
+    uint32_t version_ = 0;
+
+    DISALLOW_COPY_AND_ASSIGN(Slot);
+  };
+
+ private:
+  // In most cases, most callers should not need access to HasBeenDestroyed().
+  // If you are working in code that runs during thread destruction, contact the
+  // base OWNERs for advice and then make a friend request.
+  //
+  // Returns |true| if Chrome's implementation of TLS is being or has been
+  // destroyed during thread destruction. Attempting to call Slot::Get() during
+  // destruction is disallowed and will hit a DCHECK. Any code that relies on
+  // TLS during thread destruction must first check this method before calling
+  // Slot::Get().
+  friend class SequenceCheckerImpl;
+  friend class SamplingHeapProfiler;
+  friend class ThreadCheckerImpl;
+  friend class internal::ThreadLocalStorageTestInternal;
+  friend class trace_event::MallocDumpProvider;
+  friend class debug::GlobalActivityTracker;
+  friend class ui::TLSDestructionCheckerForX11;
+  static bool HasBeenDestroyed();
+
+  DISALLOW_COPY_AND_ASSIGN(ThreadLocalStorage);
+};
+
+}  // namespace base
+
+#endif  // BASE_THREADING_THREAD_LOCAL_STORAGE_H_
diff --git a/security/sandbox/chromium/base/threading/thread_local_storage_posix.cc b/security/sandbox/chromium/base/threading/thread_local_storage_posix.cc
new file mode 100644
index 0000000000..89edeee1d2
--- /dev/null
+++ b/security/sandbox/chromium/base/threading/thread_local_storage_posix.cc
@@ -0,0 +1,30 @@
+// 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/threading/thread_local_storage.h"
+
+#include "base/logging.h"
+
+namespace base {
+
+namespace internal {
+
+bool PlatformThreadLocalStorage::AllocTLS(TLSKey* key) {
+  return !pthread_key_create(key,
+      base::internal::PlatformThreadLocalStorage::OnThreadExit);
+}
+
+void PlatformThreadLocalStorage::FreeTLS(TLSKey key) {
+  int ret = pthread_key_delete(key);
+  DCHECK_EQ(ret, 0);
+}
+
+void PlatformThreadLocalStorage::SetTLSValue(TLSKey key, void* value) {
+  int ret = pthread_setspecific(key, value);
+  DCHECK_EQ(ret, 0);
+}
+
+}  // namespace internal
+
+}  // namespace base
diff --git a/security/sandbox/chromium/base/threading/thread_local_storage_win.cc b/security/sandbox/chromium/base/threading/thread_local_storage_win.cc
new file mode 100644
index 0000000000..a9aec31da5
--- /dev/null
+++ b/security/sandbox/chromium/base/threading/thread_local_storage_win.cc
@@ -0,0 +1,107 @@
+// 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/threading/thread_local_storage.h"
+
+#include <windows.h>
+
+#include "base/logging.h"
+
+namespace base {
+
+namespace internal {
+
+bool PlatformThreadLocalStorage::AllocTLS(TLSKey* key) {
+  TLSKey value = TlsAlloc();
+  if (value != TLS_OUT_OF_INDEXES) {
+    *key = value;
+    return true;
+  }
+  return false;
+}
+
+void PlatformThreadLocalStorage::FreeTLS(TLSKey key) {
+  BOOL ret = TlsFree(key);
+  DCHECK(ret);
+}
+
+void PlatformThreadLocalStorage::SetTLSValue(TLSKey key, void* value) {
+  BOOL ret = TlsSetValue(key, value);
+  DCHECK(ret);
+}
+
+}  // namespace internal
+
+}  // namespace base
+
+// Thread Termination Callbacks.
+// Windows doesn't support a per-thread destructor with its
+// TLS primitives.  So, we build it manually by inserting a
+// function to be called on each thread's exit.
+// This magic is from http://www.codeproject.com/threads/tls.asp
+// and it works for VC++ 7.0 and later.
+
+// Force a reference to _tls_used to make the linker create the TLS directory
+// if it's not already there.  (e.g. if __declspec(thread) is not used).
+// Force a reference to p_thread_callback_base to prevent whole program
+// optimization from discarding the variable.
+#ifdef _WIN64
+
+#pragma comment(linker, "/INCLUDE:_tls_used")
+#pragma comment(linker, "/INCLUDE:p_thread_callback_base")
+
+#else  // _WIN64
+
+#pragma comment(linker, "/INCLUDE:__tls_used")
+#pragma comment(linker, "/INCLUDE:_p_thread_callback_base")
+
+#endif  // _WIN64
+
+// Static callback function to call with each thread termination.
+void NTAPI OnThreadExit(PVOID module, DWORD reason, PVOID reserved) {
+  // On XP SP0 & SP1, the DLL_PROCESS_ATTACH is never seen. It is sent on SP2+
+  // and on W2K and W2K3. So don't assume it is sent.
+  if (DLL_THREAD_DETACH == reason || DLL_PROCESS_DETACH == reason)
+    base::internal::PlatformThreadLocalStorage::OnThreadExit();
+}
+
+// .CRT$XLA to .CRT$XLZ is an array of PIMAGE_TLS_CALLBACK pointers that are
+// called automatically by the OS loader code (not the CRT) when the module is
+// loaded and on thread creation. They are NOT called if the module has been
+// loaded by a LoadLibrary() call. It must have implicitly been loaded at
+// process startup.
+// By implicitly loaded, I mean that it is directly referenced by the main EXE
+// or by one of its dependent DLLs. Delay-loaded DLL doesn't count as being
+// implicitly loaded.
+//
+// See VC\crt\src\tlssup.c for reference.
+
+// extern "C" suppresses C++ name mangling so we know the symbol name for the
+// linker /INCLUDE:symbol pragma above.
+extern "C" {
+// The linker must not discard p_thread_callback_base.  (We force a reference
+// to this variable with a linker /INCLUDE:symbol pragma to ensure that.) If
+// this variable is discarded, the OnThreadExit function will never be called.
+#ifdef _WIN64
+
+// .CRT section is merged with .rdata on x64 so it must be constant data.
+#pragma const_seg(".CRT$XLB")
+// When defining a const variable, it must have external linkage to be sure the
+// linker doesn't discard it.
+extern const PIMAGE_TLS_CALLBACK p_thread_callback_base;
+const PIMAGE_TLS_CALLBACK p_thread_callback_base = OnThreadExit;
+
+// Reset the default section.
+#pragma const_seg()
+
+#else  // _WIN64
+
+#pragma data_seg(".CRT$XLB")
+PIMAGE_TLS_CALLBACK p_thread_callback_base = OnThreadExit;
+
+// Reset the default section.
+#pragma data_seg()
+
+#endif  // _WIN64
+}  // extern "C"
diff --git a/security/sandbox/chromium/base/threading/thread_restrictions.cc b/security/sandbox/chromium/base/threading/thread_restrictions.cc
new file mode 100644
index 0000000000..75c37eab4f
--- /dev/null
+++ b/security/sandbox/chromium/base/threading/thread_restrictions.cc
@@ -0,0 +1,258 @@
+// 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/threading/thread_restrictions.h"
+
+#if DCHECK_IS_ON()
+
+#include "base/debug/stack_trace.h"
+#include "base/lazy_instance.h"
+#include "base/logging.h"
+#include "base/threading/thread_local.h"
+#include "build/build_config.h"
+
+namespace base {
+
+std::ostream& operator<<(std::ostream&out, const ThreadLocalBoolean& tl) {
+  out << "currently set to " << (tl.Get() ? "true" : "false");
+  return out;
+}
+
+namespace {
+
+#if defined(OS_NACL) || defined(OS_ANDROID)
+// NaCL doesn't support stack sampling and Android is slow at stack
+// sampling and this causes timeouts (crbug.com/959139).
+using ThreadLocalBooleanWithStacks = ThreadLocalBoolean;
+#else
+class ThreadLocalBooleanWithStacks {
+ public:
+  ThreadLocalBooleanWithStacks() = default;
+
+  bool Get() const { return bool_.Get(); }
+
+  void Set(bool val) {
+    stack_.Set(std::make_unique<debug::StackTrace>());
+    bool_.Set(val);
+  }
+
+  friend std::ostream& operator<<(std::ostream& out,
+                                  const ThreadLocalBooleanWithStacks& tl) {
+    out << tl.bool_ << " by ";
+
+    if (!tl.stack_.Get())
+      return out << "default value\n";
+    out << "\n";
+    tl.stack_.Get()->OutputToStream(&out);
+    return out;
+  }
+
+ private:
+  ThreadLocalBoolean bool_;
+  ThreadLocalOwnedPointer<debug::StackTrace> stack_;
+
+  DISALLOW_COPY_AND_ASSIGN(ThreadLocalBooleanWithStacks);
+};
+#endif  // defined(OS_NACL)
+
+LazyInstance<ThreadLocalBooleanWithStacks>::Leaky g_blocking_disallowed =
+    LAZY_INSTANCE_INITIALIZER;
+
+LazyInstance<ThreadLocalBooleanWithStacks>::Leaky g_singleton_disallowed =
+    LAZY_INSTANCE_INITIALIZER;
+
+LazyInstance<ThreadLocalBooleanWithStacks>::Leaky
+    g_base_sync_primitives_disallowed = LAZY_INSTANCE_INITIALIZER;
+
+LazyInstance<ThreadLocalBooleanWithStacks>::Leaky
+    g_cpu_intensive_work_disallowed = LAZY_INSTANCE_INITIALIZER;
+
+}  // namespace
+
+namespace internal {
+
+void AssertBlockingAllowed() {
+  DCHECK(!g_blocking_disallowed.Get().Get())
+      << "Function marked as blocking was called from a scope that disallows "
+         "blocking! If this task is running inside the ThreadPool, it needs "
+         "to have MayBlock() in its TaskTraits. Otherwise, consider making "
+         "this blocking work asynchronous or, as a last resort, you may use "
+         "ScopedAllowBlocking (see its documentation for best practices).\n"
+      << "g_blocking_disallowed " << g_blocking_disallowed.Get();
+}
+
+}  // namespace internal
+
+void DisallowBlocking() {
+  g_blocking_disallowed.Get().Set(true);
+}
+
+ScopedDisallowBlocking::ScopedDisallowBlocking()
+    : was_disallowed_(g_blocking_disallowed.Get().Get()) {
+  g_blocking_disallowed.Get().Set(true);
+}
+
+ScopedDisallowBlocking::~ScopedDisallowBlocking() {
+  DCHECK(g_blocking_disallowed.Get().Get());
+  g_blocking_disallowed.Get().Set(was_disallowed_);
+}
+
+ScopedAllowBlocking::ScopedAllowBlocking()
+    : was_disallowed_(g_blocking_disallowed.Get().Get()) {
+  g_blocking_disallowed.Get().Set(false);
+}
+
+ScopedAllowBlocking::~ScopedAllowBlocking() {
+  DCHECK(!g_blocking_disallowed.Get().Get());
+  g_blocking_disallowed.Get().Set(was_disallowed_);
+}
+
+void DisallowBaseSyncPrimitives() {
+  g_base_sync_primitives_disallowed.Get().Set(true);
+}
+
+ScopedAllowBaseSyncPrimitives::ScopedAllowBaseSyncPrimitives()
+    : was_disallowed_(g_base_sync_primitives_disallowed.Get().Get()) {
+  DCHECK(!g_blocking_disallowed.Get().Get())
+      << "To allow //base sync primitives in a scope where blocking is "
+         "disallowed use ScopedAllowBaseSyncPrimitivesOutsideBlockingScope.\n"
+      << "g_blocking_disallowed " << g_blocking_disallowed.Get();
+  g_base_sync_primitives_disallowed.Get().Set(false);
+}
+
+ScopedAllowBaseSyncPrimitives::~ScopedAllowBaseSyncPrimitives() {
+  DCHECK(!g_base_sync_primitives_disallowed.Get().Get());
+  g_base_sync_primitives_disallowed.Get().Set(was_disallowed_);
+}
+
+ScopedAllowBaseSyncPrimitivesOutsideBlockingScope::
+    ScopedAllowBaseSyncPrimitivesOutsideBlockingScope()
+    : was_disallowed_(g_base_sync_primitives_disallowed.Get().Get()) {
+  g_base_sync_primitives_disallowed.Get().Set(false);
+}
+
+ScopedAllowBaseSyncPrimitivesOutsideBlockingScope::
+    ~ScopedAllowBaseSyncPrimitivesOutsideBlockingScope() {
+  DCHECK(!g_base_sync_primitives_disallowed.Get().Get());
+  g_base_sync_primitives_disallowed.Get().Set(was_disallowed_);
+}
+
+ScopedAllowBaseSyncPrimitivesForTesting::
+    ScopedAllowBaseSyncPrimitivesForTesting()
+    : was_disallowed_(g_base_sync_primitives_disallowed.Get().Get()) {
+  g_base_sync_primitives_disallowed.Get().Set(false);
+}
+
+ScopedAllowBaseSyncPrimitivesForTesting::
+    ~ScopedAllowBaseSyncPrimitivesForTesting() {
+  DCHECK(!g_base_sync_primitives_disallowed.Get().Get());
+  g_base_sync_primitives_disallowed.Get().Set(was_disallowed_);
+}
+
+ScopedAllowUnresponsiveTasksForTesting::ScopedAllowUnresponsiveTasksForTesting()
+    : was_disallowed_base_sync_(g_base_sync_primitives_disallowed.Get().Get()),
+      was_disallowed_blocking_(g_blocking_disallowed.Get().Get()),
+      was_disallowed_cpu_(g_cpu_intensive_work_disallowed.Get().Get()) {
+  g_base_sync_primitives_disallowed.Get().Set(false);
+  g_blocking_disallowed.Get().Set(false);
+  g_cpu_intensive_work_disallowed.Get().Set(false);
+}
+
+ScopedAllowUnresponsiveTasksForTesting::
+    ~ScopedAllowUnresponsiveTasksForTesting() {
+  DCHECK(!g_base_sync_primitives_disallowed.Get().Get());
+  DCHECK(!g_blocking_disallowed.Get().Get());
+  DCHECK(!g_cpu_intensive_work_disallowed.Get().Get());
+  g_base_sync_primitives_disallowed.Get().Set(was_disallowed_base_sync_);
+  g_blocking_disallowed.Get().Set(was_disallowed_blocking_);
+  g_cpu_intensive_work_disallowed.Get().Set(was_disallowed_cpu_);
+}
+
+namespace internal {
+
+void AssertBaseSyncPrimitivesAllowed() {
+  DCHECK(!g_base_sync_primitives_disallowed.Get().Get())
+      << "Waiting on a //base sync primitive is not allowed on this thread to "
+         "prevent jank and deadlock. If waiting on a //base sync primitive is "
+         "unavoidable, do it within the scope of a "
+         "ScopedAllowBaseSyncPrimitives. If in a test, "
+         "use ScopedAllowBaseSyncPrimitivesForTesting.\n"
+      << "g_base_sync_primitives_disallowed "
+      << g_base_sync_primitives_disallowed.Get()
+      << "It can be useful to know that g_blocking_disallowed is "
+      << g_blocking_disallowed.Get();
+}
+
+void ResetThreadRestrictionsForTesting() {
+  g_blocking_disallowed.Get().Set(false);
+  g_singleton_disallowed.Get().Set(false);
+  g_base_sync_primitives_disallowed.Get().Set(false);
+  g_cpu_intensive_work_disallowed.Get().Set(false);
+}
+
+}  // namespace internal
+
+void AssertLongCPUWorkAllowed() {
+  DCHECK(!g_cpu_intensive_work_disallowed.Get().Get())
+      << "Function marked as CPU intensive was called from a scope that "
+         "disallows this kind of work! Consider making this work "
+         "asynchronous.\n"
+      << "g_cpu_intensive_work_disallowed "
+      << g_cpu_intensive_work_disallowed.Get();
+}
+
+void DisallowUnresponsiveTasks() {
+  DisallowBlocking();
+  DisallowBaseSyncPrimitives();
+  g_cpu_intensive_work_disallowed.Get().Set(true);
+}
+
+ThreadRestrictions::ScopedAllowIO::ScopedAllowIO()
+    : was_allowed_(SetIOAllowed(true)) {}
+
+ThreadRestrictions::ScopedAllowIO::~ScopedAllowIO() {
+  SetIOAllowed(was_allowed_);
+}
+
+// static
+bool ThreadRestrictions::SetIOAllowed(bool allowed) {
+  bool previous_disallowed = g_blocking_disallowed.Get().Get();
+  g_blocking_disallowed.Get().Set(!allowed);
+  return !previous_disallowed;
+}
+
+// static
+bool ThreadRestrictions::SetSingletonAllowed(bool allowed) {
+  bool previous_disallowed = g_singleton_disallowed.Get().Get();
+  g_singleton_disallowed.Get().Set(!allowed);
+  return !previous_disallowed;
+}
+
+// static
+void ThreadRestrictions::AssertSingletonAllowed() {
+  DCHECK(!g_singleton_disallowed.Get().Get())
+      << "LazyInstance/Singleton is not allowed to be used on this thread. "
+         "Most likely it's because this thread is not joinable (or the current "
+         "task is running with TaskShutdownBehavior::CONTINUE_ON_SHUTDOWN "
+         "semantics), so AtExitManager may have deleted the object on "
+         "shutdown, leading to a potential shutdown crash. If you need to use "
+         "the object from this context, it'll have to be updated to use Leaky "
+         "traits.\n"
+      << "g_singleton_disallowed " << g_singleton_disallowed.Get();
+}
+
+// static
+void ThreadRestrictions::DisallowWaiting() {
+  DisallowBaseSyncPrimitives();
+}
+
+bool ThreadRestrictions::SetWaitAllowed(bool allowed) {
+  bool previous_disallowed = g_base_sync_primitives_disallowed.Get().Get();
+  g_base_sync_primitives_disallowed.Get().Set(!allowed);
+  return !previous_disallowed;
+}
+
+}  // namespace base
+
+#endif  // DCHECK_IS_ON()
diff --git a/security/sandbox/chromium/base/threading/thread_restrictions.h b/security/sandbox/chromium/base/threading/thread_restrictions.h
new file mode 100644
index 0000000000..55047c5b40
--- /dev/null
+++ b/security/sandbox/chromium/base/threading/thread_restrictions.h
@@ -0,0 +1,680 @@
+// 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.
+
+#ifndef BASE_THREADING_THREAD_RESTRICTIONS_H_
+#define BASE_THREADING_THREAD_RESTRICTIONS_H_
+
+#include "base/base_export.h"
+#include "base/gtest_prod_util.h"
+#include "base/logging.h"
+#include "base/macros.h"
+
+// -----------------------------------------------------------------------------
+// Usage documentation
+// -----------------------------------------------------------------------------
+//
+// Overview:
+// This file exposes functions to ban and allow certain slow operations
+// on a per-thread basis. To annotate *usage* of such slow operations, refer to
+// scoped_blocking_call.h instead.
+//
+// Specific allowances that can be controlled in this file are:
+// - Blocking call: Refers to any call that causes the calling thread to wait
+//   off-CPU. It includes but is not limited to calls that wait on synchronous
+//   file I/O operations: read or write a file from disk, interact with a pipe
+//   or a socket, rename or delete a file, enumerate files in a directory, etc.
+//   Acquiring a low contention lock is not considered a blocking call.
+//
+// - Waiting on a //base sync primitive: Refers to calling one of these methods:
+//   - base::WaitableEvent::*Wait*
+//   - base::ConditionVariable::*Wait*
+//   - base::Process::WaitForExit*
+//
+// - Long CPU work: Refers to any code that takes more than 100 ms to
+//   run when there is no CPU contention and no hard page faults and therefore,
+//   is not suitable to run on a thread required to keep the browser responsive
+//   (where jank could be visible to the user).
+//
+// The following disallowance functions are offered:
+//  - DisallowBlocking(): Disallows blocking calls on the current thread.
+//  - DisallowBaseSyncPrimitives(): Disallows waiting on a //base sync primitive
+//    on the current thread.
+//  - DisallowUnresponsiveTasks() Disallows blocking calls, waiting on a //base
+//    sync primitive, and long cpu work on the current thread.
+//
+// In addition, scoped-allowance mechanisms are offered to make an exception
+// within a scope for a behavior that is normally disallowed.
+//  - ScopedAllowBlocking(ForTesting): Allows blocking calls.
+//  - ScopedAllowBaseSyncPrimitives(ForTesting)(OutsideBlockingScope): Allow
+//    waiting on a //base sync primitive. The OutsideBlockingScope suffix allows
+//    uses in a scope where blocking is also disallowed.
+//
+// Avoid using allowances outside of unit tests. In unit tests, use allowances
+// with the suffix "ForTesting".
+//
+// Prefer making blocking calls from tasks posted to base::ThreadPoolInstance
+// with base::MayBlock().
+//
+// Instead of waiting on a WaitableEvent or a ConditionVariable, prefer putting
+// the work that should happen after the wait in a continuation callback and
+// post it from where the WaitableEvent or ConditionVariable would have been
+// signaled. If something needs to be scheduled after many tasks have executed,
+// use base::BarrierClosure.
+//
+// On Windows, join processes asynchronously using base::win::ObjectWatcher.
+//
+// Where unavoidable, put ScopedAllow* instances in the narrowest scope possible
+// in the caller making the blocking call but no further down. For example: if a
+// Cleanup() method needs to do a blocking call, document Cleanup() as blocking
+// and add a ScopedAllowBlocking instance in callers that can't avoid making
+// this call from a context where blocking is banned, as such:
+//
+//   void Client::MyMethod() {
+//     (...)
+//     {
+//       // Blocking is okay here because XYZ.
+//       ScopedAllowBlocking allow_blocking;
+//       my_foo_->Cleanup();
+//     }
+//     (...)
+//   }
+//
+//   // This method can block.
+//   void Foo::Cleanup() {
+//     // Do NOT add the ScopedAllowBlocking in Cleanup() directly as that hides
+//     // its blocking nature from unknowing callers and defeats the purpose of
+//     // these checks.
+//     FlushStateToDisk();
+//   }
+//
+// Note: In rare situations where the blocking call is an implementation detail
+// (i.e. the impl makes a call that invokes AssertBlockingAllowed() but it
+// somehow knows that in practice this will not block), it might be okay to hide
+// the ScopedAllowBlocking instance in the impl with a comment explaining why
+// that's okay.
+
+class BrowserProcessImpl;
+class HistogramSynchronizer;
+class KeyStorageLinux;
+class NativeBackendKWallet;
+class NativeDesktopMediaList;
+class StartupTimeBomb;
+
+namespace android_webview {
+class AwFormDatabaseService;
+class CookieManager;
+class ScopedAllowInitGLBindings;
+class VizCompositorThreadRunnerWebView;
+}
+namespace audio {
+class OutputDevice;
+}
+namespace blink {
+class RTCVideoDecoderAdapter;
+class RTCVideoEncoder;
+class SourceStream;
+class VideoFrameResourceProvider;
+class WorkerThread;
+namespace scheduler {
+class WorkerThread;
+}
+}
+namespace cc {
+class CompletionEvent;
+class TileTaskManagerImpl;
+}
+namespace chromeos {
+class BlockingMethodCaller;
+namespace system {
+class StatisticsProviderImpl;
+}
+}
+namespace chrome_browser_net {
+class Predictor;
+}
+namespace chrome_cleaner {
+class SystemReportComponent;
+}
+namespace content {
+class BrowserGpuChannelHostFactory;
+class BrowserMainLoop;
+class BrowserProcessSubThread;
+class BrowserShutdownProfileDumper;
+class BrowserTestBase;
+class CategorizedWorkerPool;
+class DesktopCaptureDevice;
+class InProcessUtilityThread;
+class NestedMessagePumpAndroid;
+class RenderProcessHostImpl;
+class RenderWidgetHostViewMac;
+class RTCVideoDecoder;
+class SandboxHostLinux;
+class ScopedAllowWaitForDebugURL;
+class ServiceWorkerContextClient;
+class SoftwareOutputDeviceMus;
+class SynchronousCompositor;
+class SynchronousCompositorHost;
+class SynchronousCompositorSyncCallBridge;
+class TextInputClientMac;
+class WebContentsViewMac;
+}  // namespace content
+namespace cronet {
+class CronetPrefsManager;
+class CronetURLRequestContext;
+}  // namespace cronet
+namespace dbus {
+class Bus;
+}
+namespace disk_cache {
+class BackendImpl;
+class InFlightIO;
+}
+namespace functions {
+class ExecScriptScopedAllowBaseSyncPrimitives;
+}
+namespace history_report {
+class HistoryReportJniBridge;
+}
+namespace gpu {
+class GpuChannelHost;
+}
+namespace leveldb_env {
+class DBTracker;
+}
+namespace media {
+class AudioInputDevice;
+class AudioOutputDevice;
+class BlockingUrlProtocol;
+class PaintCanvasVideoRenderer;
+}
+namespace memory_instrumentation {
+class OSMetrics;
+}
+namespace midi {
+class TaskService;  // https://crbug.com/796830
+}
+namespace module_installer {
+class ScopedAllowModulePakLoad;
+}
+namespace mojo {
+class CoreLibraryInitializer;
+class SyncCallRestrictions;
+namespace core {
+class ScopedIPCSupport;
+}
+}
+namespace printing {
+class PrintJobWorker;
+class PrinterQuery;
+}
+namespace rlz_lib {
+class FinancialPing;
+}
+namespace syncer {
+class GetLocalChangesRequest;
+class HttpBridge;
+class ModelSafeWorker;
+}
+namespace ui {
+class CommandBufferClientImpl;
+class CommandBufferLocal;
+class GpuState;
+class MaterialDesignController;
+}
+namespace weblayer {
+class WebLayerPathProvider;
+}
+namespace net {
+class MultiThreadedCertVerifierScopedAllowBaseSyncPrimitives;
+class MultiThreadedProxyResolverScopedAllowJoinOnIO;
+class NetworkChangeNotifierMac;
+class NetworkConfigWatcherMacThread;
+namespace internal {
+class AddressTrackerLinux;
+}
+}
+
+namespace proxy_resolver {
+class ScopedAllowThreadJoinForProxyResolverV8Tracing;
+}
+
+namespace remoting {
+class AutoThread;
+namespace protocol {
+class ScopedAllowThreadJoinForWebRtcTransport;
+}
+}
+
+namespace resource_coordinator {
+class TabManagerDelegate;
+}
+
+namespace service_manager {
+class ServiceProcessLauncher;
+}
+
+namespace shell_integration_linux {
+class LaunchXdgUtilityScopedAllowBaseSyncPrimitives;
+}
+
+namespace ui {
+class WindowResizeHelperMac;
+}
+
+namespace viz {
+class HostGpuMemoryBufferManager;
+}
+
+namespace vr {
+class VrShell;
+}
+
+namespace web {
+class WebMainLoop;
+class WebSubThread;
+}
+
+namespace weblayer {
+class ProfileImpl;
+}
+
+namespace webrtc {
+class DesktopConfigurationMonitor;
+}
+
+namespace base {
+
+namespace sequence_manager {
+namespace internal {
+class TaskQueueImpl;
+}
+}  // namespace sequence_manager
+
+namespace android {
+class JavaHandlerThread;
+}
+
+namespace internal {
+class JobTaskSource;
+class TaskTracker;
+}
+
+class AdjustOOMScoreHelper;
+class FileDescriptorWatcher;
+class GetAppOutputScopedAllowBaseSyncPrimitives;
+class ScopedAllowThreadRecallForStackSamplingProfiler;
+class SimpleThread;
+class StackSamplingProfiler;
+class Thread;
+
+#if DCHECK_IS_ON()
+#define INLINE_IF_DCHECK_IS_OFF BASE_EXPORT
+#define EMPTY_BODY_IF_DCHECK_IS_OFF
+#else
+#define INLINE_IF_DCHECK_IS_OFF inline
+
+// The static_assert() eats follow-on semicolons. `= default` would work
+// too, but it makes clang realize that all the Scoped classes are no-ops in
+// non-dcheck builds and it starts emitting many -Wunused-variable warnings.
+#define EMPTY_BODY_IF_DCHECK_IS_OFF \
+  {}                                \
+  static_assert(true, "")
+#endif
+
+namespace internal {
+
+// Asserts that blocking calls are allowed in the current scope. This is an
+// internal call, external code should use ScopedBlockingCall instead, which
+// serves as a precise annotation of the scope that may/will block.
+INLINE_IF_DCHECK_IS_OFF void AssertBlockingAllowed()
+    EMPTY_BODY_IF_DCHECK_IS_OFF;
+
+}  // namespace internal
+
+// Disallows blocking on the current thread.
+INLINE_IF_DCHECK_IS_OFF void DisallowBlocking() EMPTY_BODY_IF_DCHECK_IS_OFF;
+
+// Disallows blocking calls within its scope.
+class BASE_EXPORT ScopedDisallowBlocking {
+ public:
+  ScopedDisallowBlocking() EMPTY_BODY_IF_DCHECK_IS_OFF;
+  ~ScopedDisallowBlocking() EMPTY_BODY_IF_DCHECK_IS_OFF;
+
+ private:
+#if DCHECK_IS_ON()
+  const bool was_disallowed_;
+#endif
+
+  DISALLOW_COPY_AND_ASSIGN(ScopedDisallowBlocking);
+};
+
+class BASE_EXPORT ScopedAllowBlocking {
+ private:
+  FRIEND_TEST_ALL_PREFIXES(ThreadRestrictionsTest, ScopedAllowBlocking);
+  friend class ScopedAllowBlockingForTesting;
+
+  // This can only be instantiated by friends. Use ScopedAllowBlockingForTesting
+  // in unit tests to avoid the friend requirement.
+  friend class AdjustOOMScoreHelper;
+  friend class android_webview::ScopedAllowInitGLBindings;
+  friend class content::BrowserProcessSubThread;
+  friend class content::RenderWidgetHostViewMac;  // http://crbug.com/121917
+  friend class content::WebContentsViewMac;
+  friend class cronet::CronetPrefsManager;
+  friend class cronet::CronetURLRequestContext;
+  friend class memory_instrumentation::OSMetrics;
+  friend class module_installer::ScopedAllowModulePakLoad;
+  friend class mojo::CoreLibraryInitializer;
+  friend class printing::PrintJobWorker;
+  friend class resource_coordinator::TabManagerDelegate;  // crbug.com/778703
+  friend class ui::MaterialDesignController;
+  friend class web::WebSubThread;
+  friend class StackSamplingProfiler;
+  friend class weblayer::ProfileImpl;
+  friend class content::RenderProcessHostImpl;
+  friend class weblayer::WebLayerPathProvider;
+
+  ScopedAllowBlocking() EMPTY_BODY_IF_DCHECK_IS_OFF;
+  ~ScopedAllowBlocking() EMPTY_BODY_IF_DCHECK_IS_OFF;
+
+#if DCHECK_IS_ON()
+  const bool was_disallowed_;
+#endif
+
+  DISALLOW_COPY_AND_ASSIGN(ScopedAllowBlocking);
+};
+
+class ScopedAllowBlockingForTesting {
+ public:
+  ScopedAllowBlockingForTesting() {}
+  ~ScopedAllowBlockingForTesting() {}
+
+ private:
+#if DCHECK_IS_ON()
+  ScopedAllowBlocking scoped_allow_blocking_;
+#endif
+
+  DISALLOW_COPY_AND_ASSIGN(ScopedAllowBlockingForTesting);
+};
+
+INLINE_IF_DCHECK_IS_OFF void DisallowBaseSyncPrimitives()
+    EMPTY_BODY_IF_DCHECK_IS_OFF;
+
+class BASE_EXPORT ScopedAllowBaseSyncPrimitives {
+ private:
+  // This can only be instantiated by friends. Use
+  // ScopedAllowBaseSyncPrimitivesForTesting in unit tests to avoid the friend
+  // requirement.
+  FRIEND_TEST_ALL_PREFIXES(ThreadRestrictionsTest,
+                           ScopedAllowBaseSyncPrimitives);
+  FRIEND_TEST_ALL_PREFIXES(ThreadRestrictionsTest,
+                           ScopedAllowBaseSyncPrimitivesResetsState);
+  FRIEND_TEST_ALL_PREFIXES(ThreadRestrictionsTest,
+                           ScopedAllowBaseSyncPrimitivesWithBlockingDisallowed);
+
+  // Allowed usage:
+  friend class SimpleThread;
+  friend class base::GetAppOutputScopedAllowBaseSyncPrimitives;
+  friend class blink::SourceStream;
+  friend class blink::WorkerThread;
+  friend class blink::scheduler::WorkerThread;
+  friend class chrome_cleaner::SystemReportComponent;
+  friend class content::BrowserMainLoop;
+  friend class content::BrowserProcessSubThread;
+  friend class content::ServiceWorkerContextClient;
+  friend class functions::ExecScriptScopedAllowBaseSyncPrimitives;
+  friend class history_report::HistoryReportJniBridge;
+  friend class internal::TaskTracker;
+  friend class leveldb_env::DBTracker;
+  friend class media::BlockingUrlProtocol;
+  friend class mojo::core::ScopedIPCSupport;
+  friend class net::MultiThreadedCertVerifierScopedAllowBaseSyncPrimitives;
+  friend class rlz_lib::FinancialPing;
+  friend class shell_integration_linux::
+      LaunchXdgUtilityScopedAllowBaseSyncPrimitives;
+  friend class syncer::HttpBridge;
+  friend class syncer::GetLocalChangesRequest;
+  friend class syncer::ModelSafeWorker;
+  friend class webrtc::DesktopConfigurationMonitor;
+
+  // Usage that should be fixed:
+  friend class ::NativeBackendKWallet;            // http://crbug.com/125331
+  friend class ::chromeos::system::
+      StatisticsProviderImpl;                      // http://crbug.com/125385
+  friend class content::TextInputClientMac;        // http://crbug.com/121917
+  friend class blink::VideoFrameResourceProvider;  // http://crbug.com/878070
+
+  ScopedAllowBaseSyncPrimitives() EMPTY_BODY_IF_DCHECK_IS_OFF;
+  ~ScopedAllowBaseSyncPrimitives() EMPTY_BODY_IF_DCHECK_IS_OFF;
+
+#if DCHECK_IS_ON()
+  const bool was_disallowed_;
+#endif
+
+  DISALLOW_COPY_AND_ASSIGN(ScopedAllowBaseSyncPrimitives);
+};
+
+class BASE_EXPORT ScopedAllowBaseSyncPrimitivesOutsideBlockingScope {
+ private:
+  // This can only be instantiated by friends. Use
+  // ScopedAllowBaseSyncPrimitivesForTesting in unit tests to avoid the friend
+  // requirement.
+  FRIEND_TEST_ALL_PREFIXES(ThreadRestrictionsTest,
+                           ScopedAllowBaseSyncPrimitivesOutsideBlockingScope);
+  FRIEND_TEST_ALL_PREFIXES(
+      ThreadRestrictionsTest,
+      ScopedAllowBaseSyncPrimitivesOutsideBlockingScopeResetsState);
+
+  // Allowed usage:
+  friend class ::BrowserProcessImpl;  // http://crbug.com/125207
+  friend class ::KeyStorageLinux;
+  friend class ::NativeDesktopMediaList;
+  friend class ::StartupTimeBomb;
+  friend class android::JavaHandlerThread;
+  friend class android_webview::
+      AwFormDatabaseService;  // http://crbug.com/904431
+  friend class android_webview::CookieManager;
+  friend class android_webview::VizCompositorThreadRunnerWebView;
+  friend class audio::OutputDevice;
+  friend class base::sequence_manager::internal::TaskQueueImpl;
+  friend class base::FileDescriptorWatcher;
+  friend class base::internal::JobTaskSource;
+  friend class base::ScopedAllowThreadRecallForStackSamplingProfiler;
+  friend class base::StackSamplingProfiler;
+  friend class blink::RTCVideoDecoderAdapter;
+  friend class blink::RTCVideoEncoder;
+  friend class cc::TileTaskManagerImpl;
+  friend class content::CategorizedWorkerPool;
+  friend class content::DesktopCaptureDevice;
+  friend class content::InProcessUtilityThread;
+  friend class content::RTCVideoDecoder;
+  friend class content::SandboxHostLinux;
+  friend class content::ScopedAllowWaitForDebugURL;
+  friend class content::SynchronousCompositor;
+  friend class content::SynchronousCompositorHost;
+  friend class content::SynchronousCompositorSyncCallBridge;
+  friend class media::AudioInputDevice;
+  friend class media::AudioOutputDevice;
+  friend class media::PaintCanvasVideoRenderer;
+  friend class mojo::SyncCallRestrictions;
+  friend class net::NetworkConfigWatcherMacThread;
+  friend class viz::HostGpuMemoryBufferManager;
+  friend class vr::VrShell;
+
+  // Usage that should be fixed:
+  friend class ::chromeos::BlockingMethodCaller;  // http://crbug.com/125360
+  friend class base::Thread;                      // http://crbug.com/918039
+  friend class cc::CompletionEvent;               // http://crbug.com/902653
+  friend class content::
+      BrowserGpuChannelHostFactory;                 // http://crbug.com/125248
+  friend class dbus::Bus;                           // http://crbug.com/125222
+  friend class disk_cache::BackendImpl;             // http://crbug.com/74623
+  friend class disk_cache::InFlightIO;              // http://crbug.com/74623
+  friend class gpu::GpuChannelHost;                 // http://crbug.com/125264
+  friend class remoting::protocol::
+      ScopedAllowThreadJoinForWebRtcTransport;      // http://crbug.com/660081
+  friend class midi::TaskService;                   // https://crbug.com/796830
+  friend class net::internal::AddressTrackerLinux;  // http://crbug.com/125097
+  friend class net::
+      MultiThreadedProxyResolverScopedAllowJoinOnIO;  // http://crbug.com/69710
+  friend class net::NetworkChangeNotifierMac;         // http://crbug.com/125097
+  friend class printing::PrinterQuery;                 // http://crbug.com/66082
+  friend class proxy_resolver::
+      ScopedAllowThreadJoinForProxyResolverV8Tracing;  // http://crbug.com/69710
+  friend class remoting::AutoThread;  // https://crbug.com/944316
+  // Not used in production yet, https://crbug.com/844078.
+  friend class service_manager::ServiceProcessLauncher;
+  friend class ui::WindowResizeHelperMac;  // http://crbug.com/902829
+
+  ScopedAllowBaseSyncPrimitivesOutsideBlockingScope()
+      EMPTY_BODY_IF_DCHECK_IS_OFF;
+  ~ScopedAllowBaseSyncPrimitivesOutsideBlockingScope()
+      EMPTY_BODY_IF_DCHECK_IS_OFF;
+
+#if DCHECK_IS_ON()
+  const bool was_disallowed_;
+#endif
+
+  DISALLOW_COPY_AND_ASSIGN(ScopedAllowBaseSyncPrimitivesOutsideBlockingScope);
+};
+
+class BASE_EXPORT ScopedAllowBaseSyncPrimitivesForTesting {
+ public:
+  ScopedAllowBaseSyncPrimitivesForTesting() EMPTY_BODY_IF_DCHECK_IS_OFF;
+  ~ScopedAllowBaseSyncPrimitivesForTesting() EMPTY_BODY_IF_DCHECK_IS_OFF;
+
+ private:
+#if DCHECK_IS_ON()
+  const bool was_disallowed_;
+#endif
+
+  DISALLOW_COPY_AND_ASSIGN(ScopedAllowBaseSyncPrimitivesForTesting);
+};
+
+// Counterpart to base::DisallowUnresponsiveTasks() for tests to allow them to
+// block their thread after it was banned.
+class BASE_EXPORT ScopedAllowUnresponsiveTasksForTesting {
+ public:
+  ScopedAllowUnresponsiveTasksForTesting() EMPTY_BODY_IF_DCHECK_IS_OFF;
+  ~ScopedAllowUnresponsiveTasksForTesting() EMPTY_BODY_IF_DCHECK_IS_OFF;
+
+ private:
+#if DCHECK_IS_ON()
+  const bool was_disallowed_base_sync_;
+  const bool was_disallowed_blocking_;
+  const bool was_disallowed_cpu_;
+#endif
+
+  DISALLOW_COPY_AND_ASSIGN(ScopedAllowUnresponsiveTasksForTesting);
+};
+
+namespace internal {
+
+// Asserts that waiting on a //base sync primitive is allowed in the current
+// scope.
+INLINE_IF_DCHECK_IS_OFF void AssertBaseSyncPrimitivesAllowed()
+    EMPTY_BODY_IF_DCHECK_IS_OFF;
+
+// Resets all thread restrictions on the current thread.
+INLINE_IF_DCHECK_IS_OFF void ResetThreadRestrictionsForTesting()
+    EMPTY_BODY_IF_DCHECK_IS_OFF;
+
+}  // namespace internal
+
+// Asserts that running long CPU work is allowed in the current scope.
+INLINE_IF_DCHECK_IS_OFF void AssertLongCPUWorkAllowed()
+    EMPTY_BODY_IF_DCHECK_IS_OFF;
+
+INLINE_IF_DCHECK_IS_OFF void DisallowUnresponsiveTasks()
+    EMPTY_BODY_IF_DCHECK_IS_OFF;
+
+class BASE_EXPORT ThreadRestrictions {
+ public:
+  // Constructing a ScopedAllowIO temporarily allows IO for the current
+  // thread.  Doing this is almost certainly always incorrect.
+  //
+  // DEPRECATED. Use ScopedAllowBlocking(ForTesting).
+  class BASE_EXPORT ScopedAllowIO {
+   public:
+    ScopedAllowIO() EMPTY_BODY_IF_DCHECK_IS_OFF;
+    ~ScopedAllowIO() EMPTY_BODY_IF_DCHECK_IS_OFF;
+
+   private:
+#if DCHECK_IS_ON()
+    const bool was_allowed_;
+#endif
+
+    DISALLOW_COPY_AND_ASSIGN(ScopedAllowIO);
+  };
+
+#if DCHECK_IS_ON()
+  // Set whether the current thread to make IO calls.
+  // Threads start out in the *allowed* state.
+  // Returns the previous value.
+  //
+  // DEPRECATED. Use ScopedAllowBlocking(ForTesting) or ScopedDisallowBlocking.
+  static bool SetIOAllowed(bool allowed);
+
+  // Set whether the current thread can use singletons.  Returns the previous
+  // value.
+  static bool SetSingletonAllowed(bool allowed);
+
+  // Check whether the current thread is allowed to use singletons (Singleton /
+  // LazyInstance).  DCHECKs if not.
+  static void AssertSingletonAllowed();
+
+  // Disable waiting on the current thread. Threads start out in the *allowed*
+  // state. Returns the previous value.
+  //
+  // DEPRECATED. Use DisallowBaseSyncPrimitives.
+  static void DisallowWaiting();
+#else
+  // Inline the empty definitions of these functions so that they can be
+  // compiled out.
+  static bool SetIOAllowed(bool allowed) { return true; }
+  static bool SetSingletonAllowed(bool allowed) { return true; }
+  static void AssertSingletonAllowed() {}
+  static void DisallowWaiting() {}
+#endif
+
+ private:
+  // DO NOT ADD ANY OTHER FRIEND STATEMENTS.
+  // BEGIN ALLOWED USAGE.
+  friend class content::BrowserMainLoop;
+  friend class content::BrowserShutdownProfileDumper;
+  friend class content::BrowserTestBase;
+  friend class content::ScopedAllowWaitForDebugURL;
+  friend class ::HistogramSynchronizer;
+  friend class internal::TaskTracker;
+  friend class web::WebMainLoop;
+  friend class MessagePumpDefault;
+  friend class PlatformThread;
+  friend class ui::CommandBufferClientImpl;
+  friend class ui::CommandBufferLocal;
+  friend class ui::GpuState;
+
+  // END ALLOWED USAGE.
+  // BEGIN USAGE THAT NEEDS TO BE FIXED.
+  friend class chrome_browser_net::Predictor;     // http://crbug.com/78451
+#if !defined(OFFICIAL_BUILD)
+  friend class content::SoftwareOutputDeviceMus;  // Interim non-production code
+#endif
+// END USAGE THAT NEEDS TO BE FIXED.
+
+#if DCHECK_IS_ON()
+  // DEPRECATED. Use ScopedAllowBaseSyncPrimitives.
+  static bool SetWaitAllowed(bool allowed);
+#else
+  static bool SetWaitAllowed(bool allowed) { return true; }
+#endif
+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(ThreadRestrictions);
+};
+
+#undef INLINE_IF_DCHECK_IS_OFF
+#undef EMPTY_BODY_IF_DCHECK_IS_OFF
+
+}  // namespace base
+
+#endif  // BASE_THREADING_THREAD_RESTRICTIONS_H_