Adding upstream version 124.0.1.upstream/124.0.1

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

10 files changed, 1463 insertions, 0 deletions

diff --git a/third_party/libwebrtc/rtc_base/memory/BUILD.gn b/third_party/libwebrtc/rtc_base/memory/BUILD.gn
new file mode 100644
index 0000000000..ee3baa40fb
--- /dev/null
+++ b/third_party/libwebrtc/rtc_base/memory/BUILD.gn
@@ -0,0 +1,61 @@
+# Copyright (c) 2018 The WebRTC project authors. All Rights Reserved.
+#
+# Use of this source code is governed by a BSD-style license
+# that can be found in the LICENSE file in the root of the source
+# tree. An additional intellectual property rights grant can be found
+# in the file PATENTS.  All contributing project authors may
+# be found in the AUTHORS file in the root of the source tree.
+
+import("../../webrtc.gni")
+if (is_android) {
+  import("//build/config/android/config.gni")
+  import("//build/config/android/rules.gni")
+}
+
+rtc_library("aligned_malloc") {
+  sources = [
+    "aligned_malloc.cc",
+    "aligned_malloc.h",
+  ]
+  deps = [ "..:checks" ]
+}
+
+# Test only utility.
+rtc_library("fifo_buffer") {
+  testonly = true
+  visibility = [
+    ":unittests",
+    "..:rtc_base_tests_utils",
+    "..:rtc_base_unittests",
+  ]
+  sources = [
+    "fifo_buffer.cc",
+    "fifo_buffer.h",
+  ]
+  deps = [
+    "..:stream",
+    "..:threading",
+    "../../api/task_queue:pending_task_safety_flag",
+    "../synchronization:mutex",
+  ]
+}
+
+rtc_library("unittests") {
+  testonly = true
+  sources = [
+    "aligned_malloc_unittest.cc",
+    "always_valid_pointer_unittest.cc",
+    "fifo_buffer_unittest.cc",
+  ]
+  deps = [
+    ":aligned_malloc",
+    ":always_valid_pointer",
+    ":fifo_buffer",
+    "../../test:test_support",
+  ]
+}
+
+rtc_source_set("always_valid_pointer") {
+  sources = [ "always_valid_pointer.h" ]
+  deps = [ "..:checks" ]
+}
diff --git a/third_party/libwebrtc/rtc_base/memory/aligned_malloc.cc b/third_party/libwebrtc/rtc_base/memory/aligned_malloc.cc
new file mode 100644
index 0000000000..7add079398
--- /dev/null
+++ b/third_party/libwebrtc/rtc_base/memory/aligned_malloc.cc
@@ -0,0 +1,98 @@
+/*
+ *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "rtc_base/memory/aligned_malloc.h"
+
+#include <stdlib.h>  // for free, malloc
+#include <string.h>  // for memcpy
+
+#include "rtc_base/checks.h"
+
+#ifdef _WIN32
+#include <windows.h>
+#else
+#include <stdint.h>
+#endif
+
+// Reference on memory alignment:
+// http://stackoverflow.com/questions/227897/solve-the-memory-alignment-in-c-interview-question-that-stumped-me
+namespace webrtc {
+
+uintptr_t GetRightAlign(uintptr_t start_pos, size_t alignment) {
+  // The pointer should be aligned with `alignment` bytes. The - 1 guarantees
+  // that it is aligned towards the closest higher (right) address.
+  return (start_pos + alignment - 1) & ~(alignment - 1);
+}
+
+// Alignment must be an integer power of two.
+bool ValidAlignment(size_t alignment) {
+  if (!alignment) {
+    return false;
+  }
+  return (alignment & (alignment - 1)) == 0;
+}
+
+void* GetRightAlign(const void* pointer, size_t alignment) {
+  if (!pointer) {
+    return NULL;
+  }
+  if (!ValidAlignment(alignment)) {
+    return NULL;
+  }
+  uintptr_t start_pos = reinterpret_cast<uintptr_t>(pointer);
+  return reinterpret_cast<void*>(GetRightAlign(start_pos, alignment));
+}
+
+void* AlignedMalloc(size_t size, size_t alignment) {
+  if (size == 0) {
+    return NULL;
+  }
+  if (!ValidAlignment(alignment)) {
+    return NULL;
+  }
+
+  // The memory is aligned towards the lowest address that so only
+  // alignment - 1 bytes needs to be allocated.
+  // A pointer to the start of the memory must be stored so that it can be
+  // retreived for deletion, ergo the sizeof(uintptr_t).
+  void* memory_pointer = malloc(size + sizeof(uintptr_t) + alignment - 1);
+  RTC_CHECK(memory_pointer) << "Couldn't allocate memory in AlignedMalloc";
+
+  // Aligning after the sizeof(uintptr_t) bytes will leave room for the header
+  // in the same memory block.
+  uintptr_t align_start_pos = reinterpret_cast<uintptr_t>(memory_pointer);
+  align_start_pos += sizeof(uintptr_t);
+  uintptr_t aligned_pos = GetRightAlign(align_start_pos, alignment);
+  void* aligned_pointer = reinterpret_cast<void*>(aligned_pos);
+
+  // Store the address to the beginning of the memory just before the aligned
+  // memory.
+  uintptr_t header_pos = aligned_pos - sizeof(uintptr_t);
+  void* header_pointer = reinterpret_cast<void*>(header_pos);
+  uintptr_t memory_start = reinterpret_cast<uintptr_t>(memory_pointer);
+  memcpy(header_pointer, &memory_start, sizeof(uintptr_t));
+
+  return aligned_pointer;
+}
+
+void AlignedFree(void* mem_block) {
+  if (mem_block == NULL) {
+    return;
+  }
+  uintptr_t aligned_pos = reinterpret_cast<uintptr_t>(mem_block);
+  uintptr_t header_pos = aligned_pos - sizeof(uintptr_t);
+
+  // Read out the address of the AlignedMemory struct from the header.
+  uintptr_t memory_start_pos = *reinterpret_cast<uintptr_t*>(header_pos);
+  void* memory_start = reinterpret_cast<void*>(memory_start_pos);
+  free(memory_start);
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/rtc_base/memory/aligned_malloc.h b/third_party/libwebrtc/rtc_base/memory/aligned_malloc.h
new file mode 100644
index 0000000000..1c7d303885
--- /dev/null
+++ b/third_party/libwebrtc/rtc_base/memory/aligned_malloc.h
@@ -0,0 +1,57 @@
+/*
+ *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef RTC_BASE_MEMORY_ALIGNED_MALLOC_H_
+#define RTC_BASE_MEMORY_ALIGNED_MALLOC_H_
+
+// The functions declared here
+// 1) Allocates block of aligned memory.
+// 2) Re-calculates a pointer such that it is aligned to a higher or equal
+//    address.
+// Note: alignment must be a power of two. The alignment is in bytes.
+
+#include <stddef.h>
+
+namespace webrtc {
+
+// Returns a pointer to the first boundry of `alignment` bytes following the
+// address of `ptr`.
+// Note that there is no guarantee that the memory in question is available.
+// `ptr` has no requirements other than it can't be NULL.
+void* GetRightAlign(const void* ptr, size_t alignment);
+
+// Allocates memory of `size` bytes aligned on an `alignment` boundry.
+// The return value is a pointer to the memory. Note that the memory must
+// be de-allocated using AlignedFree.
+void* AlignedMalloc(size_t size, size_t alignment);
+// De-allocates memory created using the AlignedMalloc() API.
+void AlignedFree(void* mem_block);
+
+// Templated versions to facilitate usage of aligned malloc without casting
+// to and from void*.
+template <typename T>
+T* GetRightAlign(const T* ptr, size_t alignment) {
+  return reinterpret_cast<T*>(
+      GetRightAlign(reinterpret_cast<const void*>(ptr), alignment));
+}
+template <typename T>
+T* AlignedMalloc(size_t size, size_t alignment) {
+  return reinterpret_cast<T*>(AlignedMalloc(size, alignment));
+}
+
+// Deleter for use with unique_ptr. E.g., use as
+//   std::unique_ptr<Foo, AlignedFreeDeleter> foo;
+struct AlignedFreeDeleter {
+  inline void operator()(void* ptr) const { AlignedFree(ptr); }
+};
+
+}  // namespace webrtc
+
+#endif  // RTC_BASE_MEMORY_ALIGNED_MALLOC_H_
diff --git a/third_party/libwebrtc/rtc_base/memory/aligned_malloc_gn/moz.build b/third_party/libwebrtc/rtc_base/memory/aligned_malloc_gn/moz.build
new file mode 100644
index 0000000000..f5720480dd
--- /dev/null
+++ b/third_party/libwebrtc/rtc_base/memory/aligned_malloc_gn/moz.build
@@ -0,0 +1,225 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+  ### This moz.build was AUTOMATICALLY GENERATED from a GN config,  ###
+  ### DO NOT edit it by hand.                                       ###
+
+COMPILE_FLAGS["OS_INCLUDES"] = []
+AllowCompilerWarnings()
+
+DEFINES["ABSL_ALLOCATOR_NOTHROW"] = "1"
+DEFINES["RTC_DAV1D_IN_INTERNAL_DECODER_FACTORY"] = True
+DEFINES["RTC_ENABLE_VP9"] = True
+DEFINES["WEBRTC_ENABLE_PROTOBUF"] = "0"
+DEFINES["WEBRTC_LIBRARY_IMPL"] = True
+DEFINES["WEBRTC_MOZILLA_BUILD"] = True
+DEFINES["WEBRTC_NON_STATIC_TRACE_EVENT_HANDLERS"] = "0"
+DEFINES["WEBRTC_STRICT_FIELD_TRIALS"] = "0"
+
+FINAL_LIBRARY = "webrtc"
+
+
+LOCAL_INCLUDES += [
+    "!/ipc/ipdl/_ipdlheaders",
+    "!/third_party/libwebrtc/gen",
+    "/ipc/chromium/src",
+    "/third_party/libwebrtc/",
+    "/third_party/libwebrtc/third_party/abseil-cpp/",
+    "/tools/profiler/public"
+]
+
+UNIFIED_SOURCES += [
+    "/third_party/libwebrtc/rtc_base/memory/aligned_malloc.cc"
+]
+
+if not CONFIG["MOZ_DEBUG"]:
+
+    DEFINES["DYNAMIC_ANNOTATIONS_ENABLED"] = "0"
+    DEFINES["NDEBUG"] = True
+    DEFINES["NVALGRIND"] = True
+
+if CONFIG["MOZ_DEBUG"] == "1":
+
+    DEFINES["DYNAMIC_ANNOTATIONS_ENABLED"] = "1"
+
+if CONFIG["OS_TARGET"] == "Android":
+
+    DEFINES["ANDROID"] = True
+    DEFINES["ANDROID_NDK_VERSION_ROLL"] = "r22_1"
+    DEFINES["HAVE_SYS_UIO_H"] = True
+    DEFINES["WEBRTC_ANDROID"] = True
+    DEFINES["WEBRTC_ANDROID_OPENSLES"] = True
+    DEFINES["WEBRTC_ENABLE_LIBEVENT"] = True
+    DEFINES["WEBRTC_LINUX"] = True
+    DEFINES["WEBRTC_POSIX"] = True
+    DEFINES["_GNU_SOURCE"] = True
+    DEFINES["__STDC_CONSTANT_MACROS"] = True
+    DEFINES["__STDC_FORMAT_MACROS"] = True
+
+    OS_LIBS += [
+        "log"
+    ]
+
+if CONFIG["OS_TARGET"] == "Darwin":
+
+    DEFINES["WEBRTC_MAC"] = True
+    DEFINES["WEBRTC_POSIX"] = True
+    DEFINES["_LIBCPP_HAS_NO_ALIGNED_ALLOCATION"] = True
+    DEFINES["__ASSERT_MACROS_DEFINE_VERSIONS_WITHOUT_UNDERSCORES"] = "0"
+    DEFINES["__STDC_CONSTANT_MACROS"] = True
+    DEFINES["__STDC_FORMAT_MACROS"] = True
+
+if CONFIG["OS_TARGET"] == "Linux":
+
+    DEFINES["USE_AURA"] = "1"
+    DEFINES["USE_GLIB"] = "1"
+    DEFINES["USE_NSS_CERTS"] = "1"
+    DEFINES["USE_OZONE"] = "1"
+    DEFINES["USE_UDEV"] = True
+    DEFINES["WEBRTC_ENABLE_LIBEVENT"] = True
+    DEFINES["WEBRTC_LINUX"] = True
+    DEFINES["WEBRTC_POSIX"] = True
+    DEFINES["_FILE_OFFSET_BITS"] = "64"
+    DEFINES["_LARGEFILE64_SOURCE"] = True
+    DEFINES["_LARGEFILE_SOURCE"] = True
+    DEFINES["__STDC_CONSTANT_MACROS"] = True
+    DEFINES["__STDC_FORMAT_MACROS"] = True
+
+if CONFIG["OS_TARGET"] == "OpenBSD":
+
+    DEFINES["USE_GLIB"] = "1"
+    DEFINES["USE_OZONE"] = "1"
+    DEFINES["USE_X11"] = "1"
+    DEFINES["WEBRTC_BSD"] = True
+    DEFINES["WEBRTC_ENABLE_LIBEVENT"] = True
+    DEFINES["WEBRTC_POSIX"] = True
+    DEFINES["_FILE_OFFSET_BITS"] = "64"
+    DEFINES["_LARGEFILE64_SOURCE"] = True
+    DEFINES["_LARGEFILE_SOURCE"] = True
+    DEFINES["__STDC_CONSTANT_MACROS"] = True
+    DEFINES["__STDC_FORMAT_MACROS"] = True
+
+if CONFIG["OS_TARGET"] == "WINNT":
+
+    DEFINES["CERT_CHAIN_PARA_HAS_EXTRA_FIELDS"] = True
+    DEFINES["NOMINMAX"] = True
+    DEFINES["NTDDI_VERSION"] = "0x0A000000"
+    DEFINES["PSAPI_VERSION"] = "2"
+    DEFINES["RTC_ENABLE_WIN_WGC"] = True
+    DEFINES["UNICODE"] = True
+    DEFINES["USE_AURA"] = "1"
+    DEFINES["WEBRTC_WIN"] = True
+    DEFINES["WIN32"] = True
+    DEFINES["WIN32_LEAN_AND_MEAN"] = True
+    DEFINES["WINAPI_FAMILY"] = "WINAPI_FAMILY_DESKTOP_APP"
+    DEFINES["WINVER"] = "0x0A00"
+    DEFINES["_ATL_NO_OPENGL"] = True
+    DEFINES["_CRT_RAND_S"] = True
+    DEFINES["_CRT_SECURE_NO_DEPRECATE"] = True
+    DEFINES["_ENABLE_EXTENDED_ALIGNED_STORAGE"] = True
+    DEFINES["_HAS_EXCEPTIONS"] = "0"
+    DEFINES["_HAS_NODISCARD"] = True
+    DEFINES["_SCL_SECURE_NO_DEPRECATE"] = True
+    DEFINES["_SECURE_ATL"] = True
+    DEFINES["_UNICODE"] = True
+    DEFINES["_WIN32_WINNT"] = "0x0A00"
+    DEFINES["_WINDOWS"] = True
+    DEFINES["__STD_C"] = True
+
+if CONFIG["TARGET_CPU"] == "aarch64":
+
+    DEFINES["WEBRTC_ARCH_ARM64"] = True
+    DEFINES["WEBRTC_HAS_NEON"] = True
+
+if CONFIG["TARGET_CPU"] == "arm":
+
+    CXXFLAGS += [
+        "-mfpu=neon"
+    ]
+
+    DEFINES["WEBRTC_ARCH_ARM"] = True
+    DEFINES["WEBRTC_ARCH_ARM_V7"] = True
+    DEFINES["WEBRTC_HAS_NEON"] = True
+
+if CONFIG["TARGET_CPU"] == "mips32":
+
+    DEFINES["MIPS32_LE"] = True
+    DEFINES["MIPS_FPU_LE"] = True
+    DEFINES["_GNU_SOURCE"] = True
+
+if CONFIG["TARGET_CPU"] == "mips64":
+
+    DEFINES["_GNU_SOURCE"] = True
+
+if CONFIG["TARGET_CPU"] == "x86":
+
+    DEFINES["WEBRTC_ENABLE_AVX2"] = True
+
+if CONFIG["TARGET_CPU"] == "x86_64":
+
+    DEFINES["WEBRTC_ENABLE_AVX2"] = True
+
+if CONFIG["MOZ_DEBUG"] == "1" and CONFIG["OS_TARGET"] == "Android":
+
+    DEFINES["_DEBUG"] = True
+
+if CONFIG["MOZ_DEBUG"] == "1" and CONFIG["OS_TARGET"] == "Darwin":
+
+    DEFINES["_DEBUG"] = True
+
+if CONFIG["MOZ_DEBUG"] == "1" and CONFIG["OS_TARGET"] == "Linux":
+
+    DEFINES["_DEBUG"] = True
+
+if CONFIG["MOZ_DEBUG"] == "1" and CONFIG["OS_TARGET"] == "OpenBSD":
+
+    DEFINES["_DEBUG"] = True
+
+if CONFIG["MOZ_DEBUG"] == "1" and CONFIG["OS_TARGET"] == "WINNT":
+
+    DEFINES["_HAS_ITERATOR_DEBUGGING"] = "0"
+
+if CONFIG["MOZ_X11"] == "1" and CONFIG["OS_TARGET"] == "Linux":
+
+    DEFINES["USE_X11"] = "1"
+
+if CONFIG["OS_TARGET"] == "Android" and CONFIG["TARGET_CPU"] == "arm":
+
+    OS_LIBS += [
+        "android_support",
+        "unwind"
+    ]
+
+if CONFIG["OS_TARGET"] == "Android" and CONFIG["TARGET_CPU"] == "x86":
+
+    CXXFLAGS += [
+        "-msse2"
+    ]
+
+    OS_LIBS += [
+        "android_support"
+    ]
+
+if CONFIG["OS_TARGET"] == "Linux" and CONFIG["TARGET_CPU"] == "aarch64":
+
+    DEFINES["_GNU_SOURCE"] = True
+
+if CONFIG["OS_TARGET"] == "Linux" and CONFIG["TARGET_CPU"] == "arm":
+
+    DEFINES["_GNU_SOURCE"] = True
+
+if CONFIG["OS_TARGET"] == "Linux" and CONFIG["TARGET_CPU"] == "x86":
+
+    CXXFLAGS += [
+        "-msse2"
+    ]
+
+    DEFINES["_GNU_SOURCE"] = True
+
+if CONFIG["OS_TARGET"] == "Linux" and CONFIG["TARGET_CPU"] == "x86_64":
+
+    DEFINES["_GNU_SOURCE"] = True
+
+Library("aligned_malloc_gn")
diff --git a/third_party/libwebrtc/rtc_base/memory/aligned_malloc_unittest.cc b/third_party/libwebrtc/rtc_base/memory/aligned_malloc_unittest.cc
new file mode 100644
index 0000000000..8e750035f0
--- /dev/null
+++ b/third_party/libwebrtc/rtc_base/memory/aligned_malloc_unittest.cc
@@ -0,0 +1,81 @@
+/*
+ *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "rtc_base/memory/aligned_malloc.h"
+
+#include <memory>
+
+#ifdef _WIN32
+#include <windows.h>
+#else
+#include <stdint.h>
+#endif
+
+#include "test/gtest.h"
+
+namespace webrtc {
+
+// Returns true if `size` and `alignment` are valid combinations.
+bool CorrectUsage(size_t size, size_t alignment) {
+  std::unique_ptr<char, AlignedFreeDeleter> scoped(
+      static_cast<char*>(AlignedMalloc(size, alignment)));
+  if (scoped.get() == NULL) {
+    return false;
+  }
+  const uintptr_t scoped_address = reinterpret_cast<uintptr_t>(scoped.get());
+  return 0u == scoped_address % alignment;
+}
+
+TEST(AlignedMalloc, GetRightAlign) {
+  const size_t size = 100;
+  const size_t alignment = 32;
+  const size_t left_misalignment = 1;
+  std::unique_ptr<char, AlignedFreeDeleter> scoped(
+      static_cast<char*>(AlignedMalloc(size, alignment)));
+  EXPECT_TRUE(scoped.get() != NULL);
+  const uintptr_t aligned_address = reinterpret_cast<uintptr_t>(scoped.get());
+  const uintptr_t misaligned_address = aligned_address - left_misalignment;
+  const char* misaligned_ptr =
+      reinterpret_cast<const char*>(misaligned_address);
+  const char* realigned_ptr = GetRightAlign(misaligned_ptr, alignment);
+  EXPECT_EQ(scoped.get(), realigned_ptr);
+}
+
+TEST(AlignedMalloc, IncorrectSize) {
+  const size_t incorrect_size = 0;
+  const size_t alignment = 64;
+  EXPECT_FALSE(CorrectUsage(incorrect_size, alignment));
+}
+
+TEST(AlignedMalloc, IncorrectAlignment) {
+  const size_t size = 100;
+  const size_t incorrect_alignment = 63;
+  EXPECT_FALSE(CorrectUsage(size, incorrect_alignment));
+}
+
+TEST(AlignedMalloc, AlignTo2Bytes) {
+  size_t size = 100;
+  size_t alignment = 2;
+  EXPECT_TRUE(CorrectUsage(size, alignment));
+}
+
+TEST(AlignedMalloc, AlignTo32Bytes) {
+  size_t size = 100;
+  size_t alignment = 32;
+  EXPECT_TRUE(CorrectUsage(size, alignment));
+}
+
+TEST(AlignedMalloc, AlignTo128Bytes) {
+  size_t size = 100;
+  size_t alignment = 128;
+  EXPECT_TRUE(CorrectUsage(size, alignment));
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/rtc_base/memory/always_valid_pointer.h b/third_party/libwebrtc/rtc_base/memory/always_valid_pointer.h
new file mode 100644
index 0000000000..4e68104b55
--- /dev/null
+++ b/third_party/libwebrtc/rtc_base/memory/always_valid_pointer.h
@@ -0,0 +1,248 @@
+/*
+ *  Copyright 2022 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+#ifndef RTC_BASE_MEMORY_ALWAYS_VALID_POINTER_H_
+#define RTC_BASE_MEMORY_ALWAYS_VALID_POINTER_H_
+
+#include <memory>
+#include <utility>
+
+#include "rtc_base/checks.h"
+
+namespace webrtc {
+
+// This template allows the instantiation of a pointer to Interface in such a
+// way that if it is passed a null pointer, an object of class Default will be
+// created, which will be deallocated when the pointer is deleted.
+template <typename Interface, typename Default = Interface>
+class AlwaysValidPointer {
+ public:
+  explicit AlwaysValidPointer(Interface* pointer)
+      : owned_instance_(pointer ? nullptr : std::make_unique<Default>()),
+        pointer_(pointer ? pointer : owned_instance_.get()) {
+    RTC_DCHECK(pointer_);
+  }
+
+  template <typename Arg,
+            typename std::enable_if<!(std::is_invocable<Arg>::value),
+                                    bool>::type = true>
+  AlwaysValidPointer(Interface* pointer, Arg arg)
+      : owned_instance_(pointer ? nullptr
+                                : std::make_unique<Default>(std::move(arg))),
+        pointer_(pointer ? pointer : owned_instance_.get()) {
+    RTC_DCHECK(pointer_);
+  }
+
+  // Multiple arguments
+  template <typename Arg1, typename... Args>
+  AlwaysValidPointer(Interface* pointer, Arg1 arg1, Args... args)
+      : owned_instance_(pointer
+                            ? nullptr
+                            : std::make_unique<Default>(std::move(arg1),
+                                                        std::move(args...))),
+        pointer_(pointer ? pointer : owned_instance_.get()) {
+    RTC_DCHECK(pointer_);
+  }
+
+  // Create a pointer by
+  // a) using |pointer|, without taking ownership
+  // b) calling |function| and taking ownership of the result
+  template <typename Func,
+            typename std::enable_if<std::is_invocable<Func>::value,
+                                    bool>::type = true>
+  AlwaysValidPointer(Interface* pointer, Func function)
+      : owned_instance_(pointer ? nullptr : function()),
+        pointer_(owned_instance_ ? owned_instance_.get() : pointer) {
+    RTC_DCHECK(pointer_);
+  }
+
+  // Create a pointer by
+  // a) taking over ownership of |instance|
+  // b) or fallback to |pointer|, without taking ownership.
+  // c) or Default.
+  AlwaysValidPointer(std::unique_ptr<Interface>&& instance, Interface* pointer)
+      : owned_instance_(
+            instance
+                ? std::move(instance)
+                : (pointer == nullptr ? std::make_unique<Default>() : nullptr)),
+        pointer_(owned_instance_ ? owned_instance_.get() : pointer) {
+    RTC_DCHECK(pointer_);
+  }
+
+  // Create a pointer by
+  // a) taking over ownership of |instance|
+  // b) or fallback to |pointer|, without taking ownership.
+  // c) or Default (with forwarded args).
+  template <typename... Args>
+  AlwaysValidPointer(std::unique_ptr<Interface>&& instance,
+                     Interface* pointer,
+                     Args... args)
+      : owned_instance_(
+            instance ? std::move(instance)
+                     : (pointer == nullptr
+                            ? std::make_unique<Default>(std::move(args...))
+                            : nullptr)),
+        pointer_(owned_instance_ ? owned_instance_.get() : pointer) {
+    RTC_DCHECK(pointer_);
+  }
+
+  Interface* get() { return pointer_; }
+  Interface* operator->() { return pointer_; }
+  Interface& operator*() { return *pointer_; }
+
+  Interface* get() const { return pointer_; }
+  Interface* operator->() const { return pointer_; }
+  Interface& operator*() const { return *pointer_; }
+
+ private:
+  const std::unique_ptr<Interface> owned_instance_;
+  Interface* const pointer_;
+};
+
+// This class is similar to AlwaysValidPointer, but it does not create
+// a default object and crashes if none of the input pointers are non-null.
+template <typename Interface>
+class AlwaysValidPointerNoDefault {
+ public:
+  explicit AlwaysValidPointerNoDefault(Interface* pointer) : pointer_(pointer) {
+    RTC_CHECK(pointer_);
+  }
+
+  // Create a pointer by
+  // a) taking over ownership of |instance|
+  // b) or fallback to |pointer|, without taking ownership.
+  // At least one of the arguments must be non-null.
+  explicit AlwaysValidPointerNoDefault(std::unique_ptr<Interface> instance,
+                                       Interface* pointer = nullptr)
+      : owned_instance_(std::move(instance)),
+        pointer_(owned_instance_ ? owned_instance_.get() : pointer) {
+    RTC_CHECK(pointer_);
+  }
+
+  Interface* get() { return pointer_; }
+  Interface* operator->() { return pointer_; }
+  Interface& operator*() { return *pointer_; }
+
+  Interface* get() const { return pointer_; }
+  Interface* operator->() const { return pointer_; }
+  Interface& operator*() const { return *pointer_; }
+
+ private:
+  const std::unique_ptr<Interface> owned_instance_;
+  Interface* const pointer_;
+};
+
+template <typename T, typename U, typename V, typename W>
+bool operator==(const AlwaysValidPointer<T, U>& a,
+                const AlwaysValidPointer<V, W>& b) {
+  return a.get() == b.get();
+}
+
+template <typename T, typename U, typename V, typename W>
+bool operator!=(const AlwaysValidPointer<T, U>& a,
+                const AlwaysValidPointer<V, W>& b) {
+  return !(a == b);
+}
+
+template <typename T, typename U>
+bool operator==(const AlwaysValidPointer<T, U>& a, std::nullptr_t) {
+  return a.get() == nullptr;
+}
+
+template <typename T, typename U>
+bool operator!=(const AlwaysValidPointer<T, U>& a, std::nullptr_t) {
+  return !(a == nullptr);
+}
+
+template <typename T, typename U>
+bool operator==(std::nullptr_t, const AlwaysValidPointer<T, U>& a) {
+  return a.get() == nullptr;
+}
+
+template <typename T, typename U>
+bool operator!=(std::nullptr_t, const AlwaysValidPointer<T, U>& a) {
+  return !(a == nullptr);
+}
+
+template <typename T, typename U>
+bool operator==(const AlwaysValidPointerNoDefault<T>& a,
+                const AlwaysValidPointerNoDefault<U>& b) {
+  return a.get() == b.get();
+}
+
+template <typename T, typename U>
+bool operator!=(const AlwaysValidPointerNoDefault<T>& a,
+                const AlwaysValidPointerNoDefault<U>& b) {
+  return !(a == b);
+}
+
+template <typename T>
+bool operator==(const AlwaysValidPointerNoDefault<T>& a, std::nullptr_t) {
+  return a.get() == nullptr;
+}
+
+template <typename T>
+bool operator!=(const AlwaysValidPointerNoDefault<T>& a, std::nullptr_t) {
+  return !(a == nullptr);
+}
+
+template <typename T>
+bool operator==(std::nullptr_t, const AlwaysValidPointerNoDefault<T>& a) {
+  return a.get() == nullptr;
+}
+
+template <typename T>
+bool operator!=(std::nullptr_t, const AlwaysValidPointerNoDefault<T>& a) {
+  return !(a == nullptr);
+}
+
+// Comparison with raw pointer.
+template <typename T, typename U, typename V>
+bool operator==(const AlwaysValidPointer<T, U>& a, const V* b) {
+  return a.get() == b;
+}
+
+template <typename T, typename U, typename V>
+bool operator!=(const AlwaysValidPointer<T, U>& a, const V* b) {
+  return !(a == b);
+}
+
+template <typename T, typename U, typename V>
+bool operator==(const T* a, const AlwaysValidPointer<U, V>& b) {
+  return a == b.get();
+}
+
+template <typename T, typename U, typename V>
+bool operator!=(const T* a, const AlwaysValidPointer<U, V>& b) {
+  return !(a == b);
+}
+
+template <typename T, typename U>
+bool operator==(const AlwaysValidPointerNoDefault<T>& a, const U* b) {
+  return a.get() == b;
+}
+
+template <typename T, typename U>
+bool operator!=(const AlwaysValidPointerNoDefault<T>& a, const U* b) {
+  return !(a == b);
+}
+
+template <typename T, typename U>
+bool operator==(const T* a, const AlwaysValidPointerNoDefault<U>& b) {
+  return a == b.get();
+}
+
+template <typename T, typename U>
+bool operator!=(const T* a, const AlwaysValidPointerNoDefault<U>& b) {
+  return !(a == b);
+}
+
+}  // namespace webrtc
+
+#endif  // RTC_BASE_MEMORY_ALWAYS_VALID_POINTER_H_
diff --git a/third_party/libwebrtc/rtc_base/memory/always_valid_pointer_unittest.cc b/third_party/libwebrtc/rtc_base/memory/always_valid_pointer_unittest.cc
new file mode 100644
index 0000000000..a228c102d0
--- /dev/null
+++ b/third_party/libwebrtc/rtc_base/memory/always_valid_pointer_unittest.cc
@@ -0,0 +1,129 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "rtc_base/memory/always_valid_pointer.h"
+
+#include <string>
+
+#include "test/gtest.h"
+
+namespace webrtc {
+
+TEST(AlwaysValidPointerTest, DefaultToEmptyValue) {
+  AlwaysValidPointer<std::string> ptr(nullptr);
+  EXPECT_EQ(*ptr, "");
+}
+TEST(AlwaysValidPointerTest, DefaultWithForwardedArgument) {
+  AlwaysValidPointer<std::string> ptr(nullptr, "test");
+  EXPECT_EQ(*ptr, "test");
+}
+TEST(AlwaysValidPointerTest, DefaultToSubclass) {
+  struct A {
+    virtual ~A() {}
+    virtual int f() = 0;
+  };
+  struct B : public A {
+    int b = 0;
+    explicit B(int val) : b(val) {}
+    virtual ~B() {}
+    int f() override { return b; }
+  };
+  AlwaysValidPointer<A, B> ptr(nullptr, 3);
+  EXPECT_EQ(ptr->f(), 3);
+  EXPECT_EQ((*ptr).f(), 3);
+  EXPECT_EQ(ptr.get()->f(), 3);
+}
+TEST(AlwaysValidPointerTest, NonDefaultValue) {
+  std::string str("keso");
+  AlwaysValidPointer<std::string> ptr(&str, "test");
+  EXPECT_EQ(*ptr, "keso");
+}
+
+TEST(AlwaysValidPointerTest, TakeOverOwnershipOfInstance) {
+  std::string str("keso");
+  std::unique_ptr<std::string> str2 = std::make_unique<std::string>("kent");
+  AlwaysValidPointer<std::string> ptr(std::move(str2), &str);
+  EXPECT_EQ(*ptr, "kent");
+  EXPECT_EQ(str2, nullptr);
+}
+
+TEST(AlwaysValidPointerTest, TakeOverOwnershipFallbackOnPointer) {
+  std::string str("keso");
+  std::unique_ptr<std::string> str2;
+  AlwaysValidPointer<std::string> ptr(std::move(str2), &str);
+  EXPECT_EQ(*ptr, "keso");
+}
+
+TEST(AlwaysValidPointerTest, TakeOverOwnershipFallbackOnDefault) {
+  std::unique_ptr<std::string> str;
+  std::string* str_ptr = nullptr;
+  AlwaysValidPointer<std::string> ptr(std::move(str), str_ptr);
+  EXPECT_EQ(*ptr, "");
+}
+
+TEST(AlwaysValidPointerTest,
+     TakeOverOwnershipFallbackOnDefaultWithForwardedArgument) {
+  std::unique_ptr<std::string> str2;
+  AlwaysValidPointer<std::string> ptr(std::move(str2), nullptr, "keso");
+  EXPECT_EQ(*ptr, "keso");
+}
+
+TEST(AlwaysValidPointerTest, TakeOverOwnershipDoesNotForwardDefaultArguments) {
+  std::unique_ptr<std::string> str = std::make_unique<std::string>("kalle");
+  std::unique_ptr<std::string> str2 = std::make_unique<std::string>("anka");
+  AlwaysValidPointer<std::string> ptr(std::move(str), nullptr, *str2);
+  EXPECT_EQ(*ptr, "kalle");
+  EXPECT_TRUE(!str);
+  EXPECT_EQ(*str2, "anka");
+}
+
+TEST(AlwaysValidPointerTest, DefaultToLambda) {
+  AlwaysValidPointer<std::string> ptr(
+      nullptr, []() { return std::make_unique<std::string>("onkel skrue"); });
+  EXPECT_EQ(*ptr, "onkel skrue");
+}
+
+TEST(AlwaysValidPointerTest, NoDefaultObjectPassValidPointer) {
+  std::string str("foo");
+  AlwaysValidPointerNoDefault<std::string> ptr(&str);
+  EXPECT_EQ(*ptr, "foo");
+  EXPECT_EQ(ptr, &str);
+}
+
+TEST(AlwaysValidPointerTest, NoDefaultObjectWithTakeOverOwnership) {
+  std::unique_ptr<std::string> str = std::make_unique<std::string>("yum");
+  AlwaysValidPointerNoDefault<std::string> ptr(std::move(str));
+  EXPECT_EQ(*ptr, "yum");
+  std::unique_ptr<std::string> str2 = std::make_unique<std::string>("fun");
+  AlwaysValidPointerNoDefault<std::string> ptr2(std::move(str), str2.get());
+  EXPECT_EQ(*ptr2, "fun");
+  EXPECT_EQ(ptr2, str2.get());
+}
+
+#if GTEST_HAS_DEATH_TEST && !defined(WEBRTC_ANDROID)
+
+TEST(AlwaysValidPointerTest, NoDefaultObjectPassNullPointer) {
+  auto pass_null = []() {
+    AlwaysValidPointerNoDefault<std::string> ptr(nullptr);
+  };
+  EXPECT_DEATH(pass_null(), "");
+}
+
+TEST(AlwaysValidPointerTest, NoDefaultObjectPassNullUniquePointer) {
+  auto pass_null = []() {
+    std::unique_ptr<std::string> str;
+    AlwaysValidPointerNoDefault<std::string> ptr(std::move(str));
+  };
+  EXPECT_DEATH(pass_null(), "");
+}
+
+#endif
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/rtc_base/memory/fifo_buffer.cc b/third_party/libwebrtc/rtc_base/memory/fifo_buffer.cc
new file mode 100644
index 0000000000..c159bc979f
--- /dev/null
+++ b/third_party/libwebrtc/rtc_base/memory/fifo_buffer.cc
@@ -0,0 +1,197 @@
+/*
+ *  Copyright 2019 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "rtc_base/memory/fifo_buffer.h"
+
+#include <algorithm>
+
+#include "rtc_base/thread.h"
+
+namespace rtc {
+
+FifoBuffer::FifoBuffer(size_t size)
+    : state_(SS_OPEN),
+      buffer_(new char[size]),
+      buffer_length_(size),
+      data_length_(0),
+      read_position_(0),
+      owner_(Thread::Current()) {
+  // all events are done on the owner_ thread
+}
+
+FifoBuffer::FifoBuffer(size_t size, Thread* owner)
+    : state_(SS_OPEN),
+      buffer_(new char[size]),
+      buffer_length_(size),
+      data_length_(0),
+      read_position_(0),
+      owner_(owner) {
+  // all events are done on the owner_ thread
+}
+
+FifoBuffer::~FifoBuffer() {}
+
+bool FifoBuffer::GetBuffered(size_t* size) const {
+  webrtc::MutexLock lock(&mutex_);
+  *size = data_length_;
+  return true;
+}
+
+StreamState FifoBuffer::GetState() const {
+  webrtc::MutexLock lock(&mutex_);
+  return state_;
+}
+
+StreamResult FifoBuffer::Read(rtc::ArrayView<uint8_t> buffer,
+                              size_t& bytes_read,
+                              int& error) {
+  webrtc::MutexLock lock(&mutex_);
+  const bool was_writable = data_length_ < buffer_length_;
+  size_t copy = 0;
+  StreamResult result = ReadLocked(buffer.data(), buffer.size(), &copy);
+
+  if (result == SR_SUCCESS) {
+    // If read was successful then adjust the read position and number of
+    // bytes buffered.
+    read_position_ = (read_position_ + copy) % buffer_length_;
+    data_length_ -= copy;
+    bytes_read = copy;
+
+    // if we were full before, and now we're not, post an event
+    if (!was_writable && copy > 0) {
+      PostEvent(SE_WRITE, 0);
+    }
+  }
+  return result;
+}
+
+StreamResult FifoBuffer::Write(rtc::ArrayView<const uint8_t> buffer,
+                               size_t& bytes_written,
+                               int& error) {
+  webrtc::MutexLock lock(&mutex_);
+
+  const bool was_readable = (data_length_ > 0);
+  size_t copy = 0;
+  StreamResult result = WriteLocked(buffer.data(), buffer.size(), &copy);
+
+  if (result == SR_SUCCESS) {
+    // If write was successful then adjust the number of readable bytes.
+    data_length_ += copy;
+    bytes_written = copy;
+    // if we didn't have any data to read before, and now we do, post an event
+    if (!was_readable && copy > 0) {
+      PostEvent(SE_READ, 0);
+    }
+  }
+  return result;
+}
+
+void FifoBuffer::Close() {
+  webrtc::MutexLock lock(&mutex_);
+  state_ = SS_CLOSED;
+}
+
+const void* FifoBuffer::GetReadData(size_t* size) {
+  webrtc::MutexLock lock(&mutex_);
+  *size = (read_position_ + data_length_ <= buffer_length_)
+              ? data_length_
+              : buffer_length_ - read_position_;
+  return &buffer_[read_position_];
+}
+
+void FifoBuffer::ConsumeReadData(size_t size) {
+  webrtc::MutexLock lock(&mutex_);
+  RTC_DCHECK(size <= data_length_);
+  const bool was_writable = data_length_ < buffer_length_;
+  read_position_ = (read_position_ + size) % buffer_length_;
+  data_length_ -= size;
+  if (!was_writable && size > 0) {
+    PostEvent(SE_WRITE, 0);
+  }
+}
+
+void* FifoBuffer::GetWriteBuffer(size_t* size) {
+  webrtc::MutexLock lock(&mutex_);
+  if (state_ == SS_CLOSED) {
+    return nullptr;
+  }
+
+  // if empty, reset the write position to the beginning, so we can get
+  // the biggest possible block
+  if (data_length_ == 0) {
+    read_position_ = 0;
+  }
+
+  const size_t write_position =
+      (read_position_ + data_length_) % buffer_length_;
+  *size = (write_position > read_position_ || data_length_ == 0)
+              ? buffer_length_ - write_position
+              : read_position_ - write_position;
+  return &buffer_[write_position];
+}
+
+void FifoBuffer::ConsumeWriteBuffer(size_t size) {
+  webrtc::MutexLock lock(&mutex_);
+  RTC_DCHECK(size <= buffer_length_ - data_length_);
+  const bool was_readable = (data_length_ > 0);
+  data_length_ += size;
+  if (!was_readable && size > 0) {
+    PostEvent(SE_READ, 0);
+  }
+}
+
+StreamResult FifoBuffer::ReadLocked(void* buffer,
+                                    size_t bytes,
+                                    size_t* bytes_read) {
+  if (data_length_ == 0) {
+    return (state_ != SS_CLOSED) ? SR_BLOCK : SR_EOS;
+  }
+
+  const size_t available = data_length_;
+  const size_t read_position = read_position_ % buffer_length_;
+  const size_t copy = std::min(bytes, available);
+  const size_t tail_copy = std::min(copy, buffer_length_ - read_position);
+  char* const p = static_cast<char*>(buffer);
+  memcpy(p, &buffer_[read_position], tail_copy);
+  memcpy(p + tail_copy, &buffer_[0], copy - tail_copy);
+
+  if (bytes_read) {
+    *bytes_read = copy;
+  }
+  return SR_SUCCESS;
+}
+
+StreamResult FifoBuffer::WriteLocked(const void* buffer,
+                                     size_t bytes,
+                                     size_t* bytes_written) {
+  if (state_ == SS_CLOSED) {
+    return SR_EOS;
+  }
+
+  if (data_length_ >= buffer_length_) {
+    return SR_BLOCK;
+  }
+
+  const size_t available = buffer_length_ - data_length_;
+  const size_t write_position =
+      (read_position_ + data_length_) % buffer_length_;
+  const size_t copy = std::min(bytes, available);
+  const size_t tail_copy = std::min(copy, buffer_length_ - write_position);
+  const char* const p = static_cast<const char*>(buffer);
+  memcpy(&buffer_[write_position], p, tail_copy);
+  memcpy(&buffer_[0], p + tail_copy, copy - tail_copy);
+
+  if (bytes_written) {
+    *bytes_written = copy;
+  }
+  return SR_SUCCESS;
+}
+
+}  // namespace rtc
diff --git a/third_party/libwebrtc/rtc_base/memory/fifo_buffer.h b/third_party/libwebrtc/rtc_base/memory/fifo_buffer.h
new file mode 100644
index 0000000000..a225c688ac
--- /dev/null
+++ b/third_party/libwebrtc/rtc_base/memory/fifo_buffer.h
@@ -0,0 +1,118 @@
+/*
+ *  Copyright 2019 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef RTC_BASE_MEMORY_FIFO_BUFFER_H_
+#define RTC_BASE_MEMORY_FIFO_BUFFER_H_
+
+#include <memory>
+
+#include "api/task_queue/pending_task_safety_flag.h"
+#include "rtc_base/stream.h"
+#include "rtc_base/synchronization/mutex.h"
+
+namespace rtc {
+
+// FifoBuffer allows for efficient, thread-safe buffering of data between
+// writer and reader.
+class FifoBuffer final : public StreamInterface {
+ public:
+  // Creates a FIFO buffer with the specified capacity.
+  explicit FifoBuffer(size_t length);
+  // Creates a FIFO buffer with the specified capacity and owner
+  FifoBuffer(size_t length, Thread* owner);
+  ~FifoBuffer() override;
+
+  FifoBuffer(const FifoBuffer&) = delete;
+  FifoBuffer& operator=(const FifoBuffer&) = delete;
+
+  // Gets the amount of data currently readable from the buffer.
+  bool GetBuffered(size_t* data_len) const;
+
+  // StreamInterface methods
+  StreamState GetState() const override;
+  StreamResult Read(rtc::ArrayView<uint8_t> buffer,
+                    size_t& bytes_read,
+                    int& error) override;
+  StreamResult Write(rtc::ArrayView<const uint8_t> buffer,
+                     size_t& bytes_written,
+                     int& error) override;
+  void Close() override;
+
+  // Seek to a byte offset from the beginning of the stream.  Returns false if
+  // the stream does not support seeking, or cannot seek to the specified
+  // position.
+  bool SetPosition(size_t position);
+
+  // Get the byte offset of the current position from the start of the stream.
+  // Returns false if the position is not known.
+  bool GetPosition(size_t* position) const;
+
+  // Seek to the start of the stream.
+  bool Rewind() { return SetPosition(0); }
+
+  // GetReadData returns a pointer to a buffer which is owned by the stream.
+  // The buffer contains data_len bytes.  null is returned if no data is
+  // available, or if the method fails.  If the caller processes the data, it
+  // must call ConsumeReadData with the number of processed bytes.  GetReadData
+  // does not require a matching call to ConsumeReadData if the data is not
+  // processed.  Read and ConsumeReadData invalidate the buffer returned by
+  // GetReadData.
+  const void* GetReadData(size_t* data_len);
+  void ConsumeReadData(size_t used);
+  // GetWriteBuffer returns a pointer to a buffer which is owned by the stream.
+  // The buffer has a capacity of buf_len bytes.  null is returned if there is
+  // no buffer available, or if the method fails.  The call may write data to
+  // the buffer, and then call ConsumeWriteBuffer with the number of bytes
+  // written.  GetWriteBuffer does not require a matching call to
+  // ConsumeWriteData if no data is written.  Write and
+  // ConsumeWriteData invalidate the buffer returned by GetWriteBuffer.
+  void* GetWriteBuffer(size_t* buf_len);
+  void ConsumeWriteBuffer(size_t used);
+
+ private:
+  void PostEvent(int events, int err) {
+    owner_->PostTask(webrtc::SafeTask(
+        task_safety_.flag(),
+        [this, events, err]() { SignalEvent(this, events, err); }));
+  }
+
+  // Helper method that implements Read. Caller must acquire a lock
+  // when calling this method.
+  StreamResult ReadLocked(void* buffer, size_t bytes, size_t* bytes_read)
+      RTC_EXCLUSIVE_LOCKS_REQUIRED(mutex_);
+
+  // Helper method that implements Write. Caller must acquire a lock
+  // when calling this method.
+  StreamResult WriteLocked(const void* buffer,
+                           size_t bytes,
+                           size_t* bytes_written)
+      RTC_EXCLUSIVE_LOCKS_REQUIRED(mutex_);
+
+  webrtc::ScopedTaskSafety task_safety_;
+
+  // keeps the opened/closed state of the stream
+  StreamState state_ RTC_GUARDED_BY(mutex_);
+  // the allocated buffer
+  std::unique_ptr<char[]> buffer_ RTC_GUARDED_BY(mutex_);
+  // size of the allocated buffer
+  const size_t buffer_length_;
+  // amount of readable data in the buffer
+  size_t data_length_ RTC_GUARDED_BY(mutex_);
+  // offset to the readable data
+  size_t read_position_ RTC_GUARDED_BY(mutex_);
+  // stream callbacks are dispatched on this thread
+  Thread* const owner_;
+  // object lock
+  mutable webrtc::Mutex mutex_;
+};
+
+}  // namespace rtc
+
+#endif  // RTC_BASE_MEMORY_FIFO_BUFFER_H_
diff --git a/third_party/libwebrtc/rtc_base/memory/fifo_buffer_unittest.cc b/third_party/libwebrtc/rtc_base/memory/fifo_buffer_unittest.cc
new file mode 100644
index 0000000000..27eb8d8b45
--- /dev/null
+++ b/third_party/libwebrtc/rtc_base/memory/fifo_buffer_unittest.cc
@@ -0,0 +1,249 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "rtc_base/memory/fifo_buffer.h"
+
+#include <string.h>
+
+#include "test/gtest.h"
+
+namespace rtc {
+
+TEST(FifoBufferTest, TestAll) {
+  rtc::AutoThread main_thread;
+  const size_t kSize = 16;
+  const uint8_t in[kSize * 2 + 1] = "0123456789ABCDEFGHIJKLMNOPQRSTUV";
+  uint8_t out[kSize * 2];
+  void* p;
+  const void* q;
+  size_t bytes;
+  FifoBuffer buf(kSize);
+
+  // Test assumptions about base state
+  EXPECT_EQ(SS_OPEN, buf.GetState());
+  int error;
+  EXPECT_EQ(SR_BLOCK, buf.Read(rtc::MakeArrayView(out, kSize), bytes, error));
+  EXPECT_TRUE(nullptr != buf.GetWriteBuffer(&bytes));
+  EXPECT_EQ(kSize, bytes);
+  buf.ConsumeWriteBuffer(0);
+
+  // Try a full write
+  EXPECT_EQ(SR_SUCCESS, buf.Write(rtc::MakeArrayView(in, kSize), bytes, error));
+  EXPECT_EQ(kSize, bytes);
+
+  // Try a write that should block
+  EXPECT_EQ(SR_BLOCK, buf.Write(rtc::MakeArrayView(in, kSize), bytes, error));
+
+  // Try a full read
+  EXPECT_EQ(SR_SUCCESS, buf.Read(rtc::MakeArrayView(out, kSize), bytes, error));
+  EXPECT_EQ(kSize, bytes);
+  EXPECT_EQ(0, memcmp(in, out, kSize));
+
+  // Try a read that should block
+  EXPECT_EQ(SR_BLOCK, buf.Read(rtc::MakeArrayView(out, kSize), bytes, error));
+
+  // Try a too-big write
+  EXPECT_EQ(SR_SUCCESS,
+            buf.Write(rtc::MakeArrayView(in, kSize * 2), bytes, error));
+  EXPECT_EQ(bytes, kSize);
+
+  // Try a too-big read
+  EXPECT_EQ(SR_SUCCESS,
+            buf.Read(rtc::MakeArrayView(out, kSize * 2), bytes, error));
+  EXPECT_EQ(kSize, bytes);
+  EXPECT_EQ(0, memcmp(in, out, kSize));
+
+  // Try some small writes and reads
+  EXPECT_EQ(SR_SUCCESS,
+            buf.Write(rtc::MakeArrayView(in, kSize / 2), bytes, error));
+  EXPECT_EQ(kSize / 2, bytes);
+  EXPECT_EQ(SR_SUCCESS,
+            buf.Read(rtc::MakeArrayView(out, kSize / 2), bytes, error));
+  EXPECT_EQ(kSize / 2, bytes);
+  EXPECT_EQ(0, memcmp(in, out, kSize / 2));
+  EXPECT_EQ(SR_SUCCESS,
+            buf.Write(rtc::MakeArrayView(in, kSize / 2), bytes, error));
+  EXPECT_EQ(kSize / 2, bytes);
+  EXPECT_EQ(SR_SUCCESS,
+            buf.Write(rtc::MakeArrayView(in, kSize / 2), bytes, error));
+  EXPECT_EQ(kSize / 2, bytes);
+  EXPECT_EQ(SR_SUCCESS,
+            buf.Read(rtc::MakeArrayView(out, kSize / 2), bytes, error));
+  EXPECT_EQ(kSize / 2, bytes);
+  EXPECT_EQ(0, memcmp(in, out, kSize / 2));
+  EXPECT_EQ(SR_SUCCESS,
+            buf.Read(rtc::MakeArrayView(out, kSize / 2), bytes, error));
+  EXPECT_EQ(kSize / 2, bytes);
+  EXPECT_EQ(0, memcmp(in, out, kSize / 2));
+
+  // Try wraparound reads and writes in the following pattern
+  // WWWWWWWWWWWW.... 0123456789AB....
+  // RRRRRRRRXXXX.... ........89AB....
+  // WWWW....XXXXWWWW 4567....89AB0123
+  // XXXX....RRRRXXXX 4567........0123
+  // XXXXWWWWWWWWXXXX 4567012345670123
+  // RRRRXXXXXXXXRRRR ....01234567....
+  // ....RRRRRRRR.... ................
+  EXPECT_EQ(SR_SUCCESS,
+            buf.Write(rtc::MakeArrayView(in, kSize * 3 / 4), bytes, error));
+  EXPECT_EQ(kSize * 3 / 4, bytes);
+  EXPECT_EQ(SR_SUCCESS,
+            buf.Read(rtc::MakeArrayView(out, kSize / 2), bytes, error));
+  EXPECT_EQ(kSize / 2, bytes);
+  EXPECT_EQ(0, memcmp(in, out, kSize / 2));
+  EXPECT_EQ(SR_SUCCESS,
+            buf.Write(rtc::MakeArrayView(in, kSize / 2), bytes, error));
+  EXPECT_EQ(kSize / 2, bytes);
+  EXPECT_EQ(SR_SUCCESS,
+            buf.Read(rtc::MakeArrayView(out, kSize / 4), bytes, error));
+  EXPECT_EQ(kSize / 4, bytes);
+  EXPECT_EQ(0, memcmp(in + kSize / 2, out, kSize / 4));
+  EXPECT_EQ(SR_SUCCESS,
+            buf.Write(rtc::MakeArrayView(in, kSize / 2), bytes, error));
+  EXPECT_EQ(kSize / 2, bytes);
+  EXPECT_EQ(SR_SUCCESS,
+            buf.Read(rtc::MakeArrayView(out, kSize / 2), bytes, error));
+  EXPECT_EQ(kSize / 2, bytes);
+  EXPECT_EQ(0, memcmp(in, out, kSize / 2));
+  EXPECT_EQ(SR_SUCCESS,
+            buf.Read(rtc::MakeArrayView(out, kSize / 2), bytes, error));
+  EXPECT_EQ(kSize / 2, bytes);
+  EXPECT_EQ(0, memcmp(in, out, kSize / 2));
+
+  // Use GetWriteBuffer to reset the read_position for the next tests
+  buf.GetWriteBuffer(&bytes);
+  buf.ConsumeWriteBuffer(0);
+
+  // Try using GetReadData to do a full read
+  EXPECT_EQ(SR_SUCCESS, buf.Write(rtc::MakeArrayView(in, kSize), bytes, error));
+  q = buf.GetReadData(&bytes);
+  EXPECT_TRUE(nullptr != q);
+  EXPECT_EQ(kSize, bytes);
+  EXPECT_EQ(0, memcmp(q, in, kSize));
+  buf.ConsumeReadData(kSize);
+  EXPECT_EQ(SR_BLOCK, buf.Read(rtc::MakeArrayView(out, kSize), bytes, error));
+
+  // Try using GetReadData to do some small reads
+  EXPECT_EQ(SR_SUCCESS, buf.Write(rtc::MakeArrayView(in, kSize), bytes, error));
+  q = buf.GetReadData(&bytes);
+  EXPECT_TRUE(nullptr != q);
+  EXPECT_EQ(kSize, bytes);
+  EXPECT_EQ(0, memcmp(q, in, kSize / 2));
+  buf.ConsumeReadData(kSize / 2);
+  q = buf.GetReadData(&bytes);
+  EXPECT_TRUE(nullptr != q);
+  EXPECT_EQ(kSize / 2, bytes);
+  EXPECT_EQ(0, memcmp(q, in + kSize / 2, kSize / 2));
+  buf.ConsumeReadData(kSize / 2);
+  EXPECT_EQ(SR_BLOCK, buf.Read(rtc::MakeArrayView(out, kSize), bytes, error));
+
+  // Try using GetReadData in a wraparound case
+  // WWWWWWWWWWWWWWWW 0123456789ABCDEF
+  // RRRRRRRRRRRRXXXX ............CDEF
+  // WWWWWWWW....XXXX 01234567....CDEF
+  // ............RRRR 01234567........
+  // RRRRRRRR........ ................
+  EXPECT_EQ(SR_SUCCESS, buf.Write(rtc::MakeArrayView(in, kSize), bytes, error));
+  EXPECT_EQ(SR_SUCCESS,
+            buf.Read(rtc::MakeArrayView(out, kSize * 3 / 4), bytes, error));
+  EXPECT_EQ(SR_SUCCESS,
+            buf.Write(rtc::MakeArrayView(in, kSize / 2), bytes, error));
+  q = buf.GetReadData(&bytes);
+  EXPECT_TRUE(nullptr != q);
+  EXPECT_EQ(kSize / 4, bytes);
+  EXPECT_EQ(0, memcmp(q, in + kSize * 3 / 4, kSize / 4));
+  buf.ConsumeReadData(kSize / 4);
+  q = buf.GetReadData(&bytes);
+  EXPECT_TRUE(nullptr != q);
+  EXPECT_EQ(kSize / 2, bytes);
+  EXPECT_EQ(0, memcmp(q, in, kSize / 2));
+  buf.ConsumeReadData(kSize / 2);
+
+  // Use GetWriteBuffer to reset the read_position for the next tests
+  buf.GetWriteBuffer(&bytes);
+  buf.ConsumeWriteBuffer(0);
+
+  // Try using GetWriteBuffer to do a full write
+  p = buf.GetWriteBuffer(&bytes);
+  EXPECT_TRUE(nullptr != p);
+  EXPECT_EQ(kSize, bytes);
+  memcpy(p, in, kSize);
+  buf.ConsumeWriteBuffer(kSize);
+  EXPECT_EQ(SR_SUCCESS, buf.Read(rtc::MakeArrayView(out, kSize), bytes, error));
+  EXPECT_EQ(kSize, bytes);
+  EXPECT_EQ(0, memcmp(in, out, kSize));
+
+  // Try using GetWriteBuffer to do some small writes
+  p = buf.GetWriteBuffer(&bytes);
+  EXPECT_TRUE(nullptr != p);
+  EXPECT_EQ(kSize, bytes);
+  memcpy(p, in, kSize / 2);
+  buf.ConsumeWriteBuffer(kSize / 2);
+  p = buf.GetWriteBuffer(&bytes);
+  EXPECT_TRUE(nullptr != p);
+  EXPECT_EQ(kSize / 2, bytes);
+  memcpy(p, in + kSize / 2, kSize / 2);
+  buf.ConsumeWriteBuffer(kSize / 2);
+  EXPECT_EQ(SR_SUCCESS, buf.Read(rtc::MakeArrayView(out, kSize), bytes, error));
+  EXPECT_EQ(kSize, bytes);
+  EXPECT_EQ(0, memcmp(in, out, kSize));
+
+  // Try using GetWriteBuffer in a wraparound case
+  // WWWWWWWWWWWW.... 0123456789AB....
+  // RRRRRRRRXXXX.... ........89AB....
+  // ........XXXXWWWW ........89AB0123
+  // WWWW....XXXXXXXX 4567....89AB0123
+  // RRRR....RRRRRRRR ................
+  EXPECT_EQ(SR_SUCCESS,
+            buf.Write(rtc::MakeArrayView(in, kSize * 3 / 4), bytes, error));
+  EXPECT_EQ(SR_SUCCESS,
+            buf.Read(rtc::MakeArrayView(out, kSize / 2), bytes, error));
+  p = buf.GetWriteBuffer(&bytes);
+  EXPECT_TRUE(nullptr != p);
+  EXPECT_EQ(kSize / 4, bytes);
+  memcpy(p, in, kSize / 4);
+  buf.ConsumeWriteBuffer(kSize / 4);
+  p = buf.GetWriteBuffer(&bytes);
+  EXPECT_TRUE(nullptr != p);
+  EXPECT_EQ(kSize / 2, bytes);
+  memcpy(p, in + kSize / 4, kSize / 4);
+  buf.ConsumeWriteBuffer(kSize / 4);
+  EXPECT_EQ(SR_SUCCESS,
+            buf.Read(rtc::MakeArrayView(out, kSize * 3 / 4), bytes, error));
+  EXPECT_EQ(kSize * 3 / 4, bytes);
+  EXPECT_EQ(0, memcmp(in + kSize / 2, out, kSize / 4));
+  EXPECT_EQ(0, memcmp(in, out + kSize / 4, kSize / 4));
+
+  // Check that the stream is now empty
+  EXPECT_EQ(SR_BLOCK, buf.Read(rtc::MakeArrayView(out, kSize), bytes, error));
+
+  // Write to the stream, close it, read the remaining bytes
+  EXPECT_EQ(SR_SUCCESS,
+            buf.Write(rtc::MakeArrayView(in, kSize / 2), bytes, error));
+  buf.Close();
+  EXPECT_EQ(SS_CLOSED, buf.GetState());
+  EXPECT_EQ(SR_EOS, buf.Write(rtc::MakeArrayView(in, kSize / 2), bytes, error));
+  EXPECT_EQ(SR_SUCCESS,
+            buf.Read(rtc::MakeArrayView(out, kSize / 2), bytes, error));
+  EXPECT_EQ(0, memcmp(in, out, kSize / 2));
+  EXPECT_EQ(SR_EOS, buf.Read(rtc::MakeArrayView(out, kSize / 2), bytes, error));
+}
+
+TEST(FifoBufferTest, FullBufferCheck) {
+  rtc::AutoThread main_thread;
+  FifoBuffer buff(10);
+  buff.ConsumeWriteBuffer(10);
+
+  size_t free;
+  EXPECT_TRUE(buff.GetWriteBuffer(&free) != nullptr);
+  EXPECT_EQ(0U, free);
+}
+
+}  // namespace rtc