diff --git a/CLOBBER b/CLOBBER
index 55db5a9a0d17..1de258b5c684 100644
--- a/CLOBBER
+++ b/CLOBBER
@@ -22,4 +22,4 @@
 # changes to stick? As of bug 928195, this shouldn't be necessary! Please
 # don't change CLOBBER for WebIDL changes any more.
 
-Modified build files in third_party/libwebrtc - Bug 1871981 - Vendor libwebrtc from 60362c144c
+Modified build files in third_party/libwebrtc - Bug 1871981 - Vendor libwebrtc from fd3b346e27
diff --git a/third_party/libwebrtc/moz.build b/third_party/libwebrtc/moz.build
index 3a72b0f16c32..ca399ca5de94 100644
--- a/third_party/libwebrtc/moz.build
+++ b/third_party/libwebrtc/moz.build
@@ -417,6 +417,7 @@ DIRS += [
     "/third_party/libwebrtc/third_party/abseil-cpp/absl/base/config_gn",
     "/third_party/libwebrtc/third_party/abseil-cpp/absl/base/core_headers_gn",
     "/third_party/libwebrtc/third_party/abseil-cpp/absl/base/log_severity_gn",
+    "/third_party/libwebrtc/third_party/abseil-cpp/absl/base/nullability_gn",
     "/third_party/libwebrtc/third_party/abseil-cpp/absl/base/raw_logging_internal_gn",
     "/third_party/libwebrtc/third_party/abseil-cpp/absl/base/throw_delegate_gn",
     "/third_party/libwebrtc/third_party/abseil-cpp/absl/cleanup/cleanup_gn",
diff --git a/third_party/libwebrtc/third_party/abseil-cpp/absl/base/nullability_gn/moz.build b/third_party/libwebrtc/third_party/abseil-cpp/absl/base/nullability_gn/moz.build
new file mode 100644
index 000000000000..04d1e20cacc1
--- /dev/null
+++ b/third_party/libwebrtc/third_party/abseil-cpp/absl/base/nullability_gn/moz.build
@@ -0,0 +1,155 @@
+# 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"
+
+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"
+]
+
+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["_GNU_SOURCE"] = True
+
+if CONFIG["OS_TARGET"] == "Darwin":
+
+    DEFINES["_LIBCPP_HAS_NO_ALIGNED_ALLOCATION"] = True
+    DEFINES["__ASSERT_MACROS_DEFINE_VERSIONS_WITHOUT_UNDERSCORES"] = "0"
+
+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["_FILE_OFFSET_BITS"] = "64"
+    DEFINES["_LARGEFILE64_SOURCE"] = True
+    DEFINES["_LARGEFILE_SOURCE"] = True
+
+if CONFIG["OS_TARGET"] == "OpenBSD":
+
+    DEFINES["USE_GLIB"] = "1"
+    DEFINES["USE_OZONE"] = "1"
+    DEFINES["USE_X11"] = "1"
+    DEFINES["_FILE_OFFSET_BITS"] = "64"
+    DEFINES["_LARGEFILE64_SOURCE"] = True
+    DEFINES["_LARGEFILE_SOURCE"] = 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["UNICODE"] = True
+    DEFINES["USE_AURA"] = "1"
+    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_NONSTDC_NO_DEPRECATE"] = True
+    DEFINES["_CRT_NONSTDC_NO_WARNINGS"] = True
+    DEFINES["_CRT_RAND_S"] = True
+    DEFINES["_CRT_SECURE_NO_DEPRECATE"] = True
+    DEFINES["_ENABLE_EXTENDED_ALIGNED_STORAGE"] = True
+    DEFINES["_HAS_EXCEPTIONS"] = "0"
+    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"] == "mips32":
+
+    DEFINES["_GNU_SOURCE"] = True
+
+if CONFIG["TARGET_CPU"] == "mips64":
+
+    DEFINES["_GNU_SOURCE"] = 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":
+
+    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":
+
+    DEFINES["_GNU_SOURCE"] = True
+
+if CONFIG["OS_TARGET"] == "Linux" and CONFIG["TARGET_CPU"] == "x86_64":
+
+    DEFINES["_GNU_SOURCE"] = True
+
+Library("nullability_gn")