This patch is a rebase of https://bugzilla.mozilla.org/attachment.cgi?id=9377318
on top of Firefox 122.0.

Fixes: https://bugzilla.mozilla.org/show_bug.cgi?id=1875201

diff --git a/third_party/libwebrtc/modules/video_coding/webrtc_libvpx_interface_gn/moz.build b/third_party/libwebrtc/modules/video_coding/webrtc_libvpx_interface_gn/moz.build
index c5dabce8b0..e325905282 100644
--- a/third_party/libwebrtc/modules/video_coding/webrtc_libvpx_interface_gn/moz.build
+++ b/third_party/libwebrtc/modules/video_coding/webrtc_libvpx_interface_gn/moz.build
@@ -5,6 +5,8 @@
 
   ### This moz.build was AUTOMATICALLY GENERATED from a GN config,  ###
   ### DO NOT edit it by hand.                                       ###
+if not CONFIG["MOZ_SYSTEM_LIBVPX"]:
+    LOCAL_INCLUDES += [ "/media/libvpx/libvpx/" ]
 
 COMPILE_FLAGS["OS_INCLUDES"] = []
 AllowCompilerWarnings()
@@ -25,7 +27,6 @@ LOCAL_INCLUDES += [
     "!/ipc/ipdl/_ipdlheaders",
     "!/third_party/libwebrtc/gen",
     "/ipc/chromium/src",
-    "/media/libvpx/libvpx/",
     "/third_party/libwebrtc/",
     "/third_party/libwebrtc/third_party/abseil-cpp/",
     "/tools/profiler/public"
diff --git a/third_party/libwebrtc/modules/video_coding/webrtc_vp8_gn/moz.build b/third_party/libwebrtc/modules/video_coding/webrtc_vp8_gn/moz.build
index 77a6b3870b..d515bc0595 100644
--- a/third_party/libwebrtc/modules/video_coding/webrtc_vp8_gn/moz.build
+++ b/third_party/libwebrtc/modules/video_coding/webrtc_vp8_gn/moz.build
@@ -5,6 +5,8 @@
 
   ### This moz.build was AUTOMATICALLY GENERATED from a GN config,  ###
   ### DO NOT edit it by hand.                                       ###
+if not CONFIG["MOZ_SYSTEM_LIBVPX"]:
+    LOCAL_INCLUDES += [ "/media/libvpx/libvpx/" ]
 
 COMPILE_FLAGS["OS_INCLUDES"] = []
 AllowCompilerWarnings()
@@ -25,7 +27,6 @@ LOCAL_INCLUDES += [
     "!/ipc/ipdl/_ipdlheaders",
     "!/third_party/libwebrtc/gen",
     "/ipc/chromium/src",
-    "/media/libvpx/libvpx/",
     "/media/libyuv/",
     "/media/libyuv/libyuv/include/",
     "/third_party/libwebrtc/",
diff --git a/third_party/libwebrtc/modules/video_coding/webrtc_vp9_gn/moz.build b/third_party/libwebrtc/modules/video_coding/webrtc_vp9_gn/moz.build
index 4bece72807..5cc8d30e1a 100644
--- a/third_party/libwebrtc/modules/video_coding/webrtc_vp9_gn/moz.build
+++ b/third_party/libwebrtc/modules/video_coding/webrtc_vp9_gn/moz.build
@@ -5,6 +5,8 @@
 
   ### This moz.build was AUTOMATICALLY GENERATED from a GN config,  ###
   ### DO NOT edit it by hand.                                       ###
+if not CONFIG["MOZ_SYSTEM_LIBVPX"]:
+    LOCAL_INCLUDES += [ "/media/libvpx/libvpx/" ]
 
 COMPILE_FLAGS["OS_INCLUDES"] = []
 AllowCompilerWarnings()
@@ -25,7 +27,6 @@ LOCAL_INCLUDES += [
     "!/ipc/ipdl/_ipdlheaders",
     "!/third_party/libwebrtc/gen",
     "/ipc/chromium/src",
-    "/media/libvpx/libvpx/",
     "/media/libyuv/",
     "/media/libyuv/libyuv/include/",
     "/third_party/libwebrtc/",
diff --git a/third_party/libwebrtc/moz.build b/third_party/libwebrtc/moz.build
index 7baea55b7e..86d4f0f288 100644
--- a/third_party/libwebrtc/moz.build
+++ b/third_party/libwebrtc/moz.build
@@ -436,7 +436,6 @@ DIRS += [
     "/third_party/libwebrtc/third_party/abseil-cpp/absl/types/span_gn",
     "/third_party/libwebrtc/third_party/abseil-cpp/absl/types/variant_gn",
     "/third_party/libwebrtc/third_party/abseil-cpp/absl/utility/utility_gn",
-    "/third_party/libwebrtc/third_party/libvpx/libvpx_gn",
     "/third_party/libwebrtc/third_party/libyuv/libyuv_gn",
     "/third_party/libwebrtc/third_party/pffft/pffft_gn",
     "/third_party/libwebrtc/third_party/rnnoise/rnn_vad_gn",