commit 06b2489a8a44a6f3f7bf4c523689a78e78b52c83
Author: Christoph Moench-Tegeder <cmt@FreeBSD.org>

    angle build target for FreeBSD

diff --git third_party/angle/angle_common_gn/moz.build third_party/angle/angle_common_gn/moz.build
index e3220891a415..b39166f60958 100644
--- third_party/angle/angle_common_gn/moz.build
+++ third_party/angle/angle_common_gn/moz.build
@@ -134,6 +134,26 @@ if CONFIG["OS_TARGET"] == "Linux":
         "/third_party/angle/src/common/system_utils_posix.cpp"
     ]
 
+if CONFIG["OS_TARGET"] == "FreeBSD":
+
+    DEFINES["ANGLE_USE_VULKAN_DISPLAY"] = True
+    DEFINES["ANGLE_VULKAN_DISPLAY_MODE_HEADLESS"] = True
+    DEFINES["USE_GLIB"] = "1"
+    DEFINES["USE_OZONE"] = "1"
+    DEFINES["_FILE_OFFSET_BITS"] = "64"
+    DEFINES["_LARGEFILE64_SOURCE"] = True
+    DEFINES["_LARGEFILE_SOURCE"] = True
+    DEFINES["__STDC_CONSTANT_MACROS"] = True
+    DEFINES["__STDC_FORMAT_MACROS"] = True
+
+    OS_LIBS += [
+        "dl"
+    ]
+
+    UNIFIED_SOURCES += [
+        "/third_party/angle/src/common/system_utils_posix.cpp"
+    ]
+
 if CONFIG["OS_TARGET"] == "OpenBSD":
 
     DEFINES["USE_GLIB"] = "1"