diff --git a/b2g/installer/Makefile.in b/b2g/installer/Makefile.in
index 57ecd93dfcc1..b71f75984a71 100644
--- a/b2g/installer/Makefile.in
+++ b/b2g/installer/Makefile.in
@@ -99,8 +99,8 @@ DEFINES += -DMOZ_RTSP
 endif
 
 DEFINES += -DMOZ_ICU_VERSION=$(MOZ_ICU_VERSION)
-ifdef MOZ_NATIVE_ICU
-DEFINES += -DMOZ_NATIVE_ICU
+ifdef MOZ_SYSTEM_ICU
+DEFINES += -DMOZ_SYSTEM_ICU
 endif
 ifdef MOZ_SHARED_ICU
 DEFINES += -DMOZ_SHARED_ICU
diff --git a/b2g/installer/package-manifest.in b/b2g/installer/package-manifest.in
index cced5bbfe41d..c937cf025412 100644
--- a/b2g/installer/package-manifest.in
+++ b/b2g/installer/package-manifest.in
@@ -71,7 +71,7 @@
 @BINPATH@/ucrtbase.dll
 #endif
 #endif
-#ifndef MOZ_NATIVE_ICU
+#ifndef MOZ_SYSTEM_ICU
 #ifdef MOZ_SHARED_ICU
 #ifdef XP_WIN
 @BINPATH@/icudt@MOZ_ICU_DBG_SUFFIX@@MOZ_ICU_VERSION@.dll
diff --git a/browser/installer/Makefile.in b/browser/installer/Makefile.in
index ba3f7032b71e..35aaabc81a92 100644
--- a/browser/installer/Makefile.in
+++ b/browser/installer/Makefile.in
@@ -31,12 +31,12 @@ DEFINES += -DMOZ_GTK3=1
 endif
 endif
 
-ifdef MOZ_NATIVE_NSPR
-DEFINES += -DMOZ_NATIVE_NSPR=1
+ifdef MOZ_SYSTEM_NSPR
+DEFINES += -DMOZ_SYSTEM_NSPR=1
 endif
 
-ifdef MOZ_NATIVE_NSS
-DEFINES += -DMOZ_NATIVE_NSS=1
+ifdef MOZ_SYSTEM_NSS
+DEFINES += -DMOZ_SYSTEM_NSS=1
 endif
 
 ifdef NSS_DISABLE_DBM
@@ -118,8 +118,8 @@ endif
 DEFINES += -DLPROJ_ROOT=$(LPROJ_ROOT)
 
 DEFINES += -DMOZ_ICU_VERSION=$(MOZ_ICU_VERSION)
-ifdef MOZ_NATIVE_ICU
-DEFINES += -DMOZ_NATIVE_ICU
+ifdef MOZ_SYSTEM_ICU
+DEFINES += -DMOZ_SYSTEM_ICU
 endif
 ifdef MOZ_SHARED_ICU
 DEFINES += -DMOZ_SHARED_ICU
diff --git a/browser/installer/package-manifest.in b/browser/installer/package-manifest.in
index 5209a6e8bae9..d45c3ccaa5a6 100644
--- a/browser/installer/package-manifest.in
+++ b/browser/installer/package-manifest.in
@@ -68,7 +68,7 @@
 #ifdef MOZ_DMD
 @BINPATH@/@DLL_PREFIX@dmd@DLL_SUFFIX@
 #endif
-#ifndef MOZ_NATIVE_NSPR
+#ifndef MOZ_SYSTEM_NSPR
 #ifndef MOZ_FOLD_LIBS
 @BINPATH@/@DLL_PREFIX@nspr4@DLL_SUFFIX@
 @BINPATH@/@DLL_PREFIX@plc4@DLL_SUFFIX@
@@ -97,7 +97,7 @@
 @BINPATH@/ucrtbase.dll
 #endif
 #endif
-#ifndef MOZ_NATIVE_ICU
+#ifndef MOZ_SYSTEM_ICU
 #ifdef MOZ_SHARED_ICU
 #ifdef XP_WIN
 @BINPATH@/icudt@MOZ_ICU_DBG_SUFFIX@@MOZ_ICU_VERSION@.dll
@@ -132,7 +132,7 @@
 @RESPATH@/update-settings.ini
 #endif
 @RESPATH@/platform.ini
-#ifndef MOZ_NATIVE_SQLITE
+#ifndef MOZ_SYSTEM_SQLITE
 #ifndef MOZ_FOLD_LIBS
 @BINPATH@/@DLL_PREFIX@mozsqlite3@DLL_SUFFIX@
 #endif
@@ -764,7 +764,7 @@
 ; NSS libraries are signed in the staging directory,
 ; meaning their .chk files are created there directly.
 ;
-#ifndef MOZ_NATIVE_NSS
+#ifndef MOZ_SYSTEM_NSS
 @BINPATH@/@DLL_PREFIX@freebl3@DLL_SUFFIX@
 @BINPATH@/@DLL_PREFIX@nss3@DLL_SUFFIX@
 @BINPATH@/@DLL_PREFIX@nssckbi@DLL_SUFFIX@
diff --git a/build/autoconf/ffi.m4 b/build/autoconf/ffi.m4
index e775c615d449..1152dc7b349a 100644
--- a/build/autoconf/ffi.m4
+++ b/build/autoconf/ffi.m4
@@ -6,9 +6,9 @@ AC_DEFUN([MOZ_CONFIG_FFI], [
 
 MOZ_ARG_ENABLE_BOOL(system-ffi,
 [  --enable-system-ffi       Use system libffi (located with pkgconfig)],
-    MOZ_NATIVE_FFI=1 )
+    MOZ_SYSTEM_FFI=1 )
 
-if test -n "$MOZ_NATIVE_FFI"; then
+if test -n "$MOZ_SYSTEM_FFI"; then
     # Vanilla libffi 3.0.9 needs a few patches from upcoming version 3.0.10
     # for non-GCC compilers.
     if test -z "$GNU_CC"; then
@@ -18,14 +18,14 @@ if test -n "$MOZ_NATIVE_FFI"; then
     fi
 fi
 
-AC_SUBST(MOZ_NATIVE_FFI)
+AC_SUBST(MOZ_SYSTEM_FFI)
 
 ])
 
 AC_DEFUN([MOZ_SUBCONFIGURE_FFI], [
 if test -z "$BUILDING_JS" -o -n "$JS_STANDALONE"; then
 
-  if test "$BUILD_CTYPES" -a -z "$MOZ_NATIVE_FFI"; then
+  if test "$BUILD_CTYPES" -a -z "$MOZ_SYSTEM_FFI"; then
     # Run the libffi 'configure' script.
     ac_configure_args="--disable-shared --enable-static --disable-raw-api"
     if test "$MOZ_DEBUG"; then
diff --git a/build/autoconf/icu.m4 b/build/autoconf/icu.m4
index 65d10cd3512d..037af7151f62 100644
--- a/build/autoconf/icu.m4
+++ b/build/autoconf/icu.m4
@@ -10,13 +10,13 @@ dnl our copy of ICU or the system provided library.
 AC_DEFUN([MOZ_CONFIG_ICU], [
 
 ICU_LIB_NAMES=
-MOZ_NATIVE_ICU=
+MOZ_SYSTEM_ICU=
 MOZ_ARG_WITH_BOOL(system-icu,
 [  --with-system-icu
                           Use system ICU (located with pkgconfig)],
-    MOZ_NATIVE_ICU=1)
+    MOZ_SYSTEM_ICU=1)
 
-if test -n "$MOZ_NATIVE_ICU"; then
+if test -n "$MOZ_SYSTEM_ICU"; then
     PKG_CHECK_MODULES(MOZ_ICU, icu-i18n >= 50.1)
     MOZ_SHARED_ICU=1
 else
@@ -24,7 +24,7 @@ else
 fi
 
 AC_SUBST_LIST(MOZ_ICU_INCLUDES)
-AC_SUBST(MOZ_NATIVE_ICU)
+AC_SUBST(MOZ_SYSTEM_ICU)
 
 MOZ_ARG_WITH_STRING(intl-api,
 [  --with-intl-api, --with-intl-api=build, --without-intl-api
@@ -83,14 +83,14 @@ if test -n "$USE_ICU"; then
         MOZ_SHARED_ICU=1
     fi
 
-    if test -z "${JS_STANDALONE}" -a -n "${JS_SHARED_LIBRARY}${MOZ_NATIVE_ICU}"; then
+    if test -z "${JS_STANDALONE}" -a -n "${JS_SHARED_LIBRARY}${MOZ_SYSTEM_ICU}"; then
         MOZ_SHARED_ICU=1
     fi
 
     AC_SUBST(MOZ_ICU_VERSION)
     AC_SUBST(MOZ_SHARED_ICU)
 
-    if test -z "$MOZ_NATIVE_ICU"; then
+    if test -z "$MOZ_SYSTEM_ICU"; then
         case "$OS_TARGET" in
             WINNT)
                 ICU_LIB_NAMES="icuin icuuc icudt"
@@ -113,7 +113,7 @@ AC_SUBST(ENABLE_INTL_API)
 AC_SUBST(USE_ICU)
 AC_SUBST_LIST(ICU_LIB_NAMES)
 
-if test -n "$USE_ICU" -a -z "$MOZ_NATIVE_ICU"; then
+if test -n "$USE_ICU" -a -z "$MOZ_SYSTEM_ICU"; then
     dnl We build ICU as a static library for non-shared js builds and as a shared library for shared js builds.
     if test -z "$MOZ_SHARED_ICU"; then
         AC_DEFINE(U_STATIC_IMPLEMENTATION)
@@ -130,7 +130,7 @@ AC_DEFUN([MOZ_SUBCONFIGURE_ICU], [
 
 if test -z "$BUILDING_JS" -o -n "$JS_STANDALONE"; then
 
-    if test -n "$USE_ICU" -a -z "$MOZ_NATIVE_ICU"; then
+    if test -n "$USE_ICU" -a -z "$MOZ_SYSTEM_ICU"; then
         # Set ICU compile options
         ICU_CPPFLAGS=""
         # don't use icu namespace automatically in client code
diff --git a/build/autoconf/jemalloc.m4 b/build/autoconf/jemalloc.m4
index b6c30c0a515e..05f5979d8278 100644
--- a/build/autoconf/jemalloc.m4
+++ b/build/autoconf/jemalloc.m4
@@ -8,7 +8,7 @@ if test -z "$BUILDING_JS" -o -n "$JS_STANDALONE"; then
 
   # Run jemalloc configure script
 
-  if test -z "$MOZ_NATIVE_JEMALLOC" -a "$MOZ_MEMORY" && test -n "$MOZ_JEMALLOC4" -o -n "$MOZ_REPLACE_MALLOC"; then
+  if test -z "$MOZ_SYSTEM_JEMALLOC" -a "$MOZ_MEMORY" && test -n "$MOZ_JEMALLOC4" -o -n "$MOZ_REPLACE_MALLOC"; then
     ac_configure_args="--build=$build --host=$target --enable-stats --with-jemalloc-prefix=je_ --disable-valgrind"
     # We're using memalign for _aligned_malloc in memory/build/mozmemory_wrap.c
     # on Windows, so just export memalign on all platforms.
diff --git a/build/autoconf/nspr-build.m4 b/build/autoconf/nspr-build.m4
index 44078f6d91f9..a641d0596b99 100644
--- a/build/autoconf/nspr-build.m4
+++ b/build/autoconf/nspr-build.m4
@@ -137,10 +137,10 @@ fi
 if test -n "$_IS_OUTER_CONFIGURE"; then
 
 if test -n "$_USE_SYSTEM_NSPR"; then
-    AM_PATH_NSPR($NSPR_MINVER, [MOZ_NATIVE_NSPR=1], [AC_MSG_ERROR([you do not have NSPR installed or your version is older than $NSPR_MINVER.])])
+    AM_PATH_NSPR($NSPR_MINVER, [MOZ_SYSTEM_NSPR=1], [AC_MSG_ERROR([you do not have NSPR installed or your version is older than $NSPR_MINVER.])])
 fi
 
-if test -n "$MOZ_NATIVE_NSPR" -o -n "$NSPR_CFLAGS" -o -n "$NSPR_LIBS"; then
+if test -n "$MOZ_SYSTEM_NSPR" -o -n "$NSPR_CFLAGS" -o -n "$NSPR_LIBS"; then
     _SAVE_CFLAGS=$CFLAGS
     CFLAGS="$CFLAGS $NSPR_CFLAGS"
     AC_TRY_COMPILE([#include "prtypes.h"],
@@ -178,8 +178,8 @@ AC_SUBST(NSPR_INCLUDE_DIR)
 AC_SUBST(NSPR_LIB_DIR)
 
 NSPR_PKGCONF_CHECK="nspr"
-if test -n "$MOZ_NATIVE_NSPR"; then
-    # piggy back on $MOZ_NATIVE_NSPR to set a variable for the nspr check for js.pc
+if test -n "$MOZ_SYSTEM_NSPR"; then
+    # piggy back on $MOZ_SYSTEM_NSPR to set a variable for the nspr check for js.pc
     NSPR_PKGCONF_CHECK="nspr >= $NSPR_MINVER"
 
     _SAVE_CFLAGS=$CFLAGS
diff --git a/build/autoconf/zlib.m4 b/build/autoconf/zlib.m4
index c23b13553123..49a2ccc8bf49 100644
--- a/build/autoconf/zlib.m4
+++ b/build/autoconf/zlib.m4
@@ -26,11 +26,11 @@ if test -z "$MOZ_ZLIB_LIBS$MOZ_ZLIB_CFLAGS$SKIP_LIBRARY_CHECKS"; then
         LDFLAGS="$MOZ_ZLIB_LIBS $LDFLAGS"
     fi
     if test -z "$ZLIB_DIR" -o "$ZLIB_DIR" = no; then
-        MOZ_NATIVE_ZLIB=
+        MOZ_SYSTEM_ZLIB=
     else
-        AC_CHECK_LIB(z, gzread, [MOZ_NATIVE_ZLIB=1 MOZ_ZLIB_LIBS="$MOZ_ZLIB_LIBS -lz"],
-            [MOZ_NATIVE_ZLIB=])
-        if test "$MOZ_NATIVE_ZLIB" = 1; then
+        AC_CHECK_LIB(z, gzread, [MOZ_SYSTEM_ZLIB=1 MOZ_ZLIB_LIBS="$MOZ_ZLIB_LIBS -lz"],
+            [MOZ_SYSTEM_ZLIB=])
+        if test "$MOZ_SYSTEM_ZLIB" = 1; then
             MOZZLIBNUM=`echo $MOZZLIB | awk -F. changequote(<<, >>)'{printf "0x%x\n", (((<<$>>1 * 16 + <<$>>2) * 16) + <<$>>3) * 16 + <<$>>4}'changequote([, ])`
             AC_TRY_COMPILE([ #include <stdio.h>
                              #include <string.h>
@@ -38,7 +38,7 @@ if test -z "$MOZ_ZLIB_LIBS$MOZ_ZLIB_CFLAGS$SKIP_LIBRARY_CHECKS"; then
                            [ #if ZLIB_VERNUM < $MOZZLIBNUM
                              #error "Insufficient zlib version ($MOZZLIBNUM required)."
                              #endif ],
-                           MOZ_NATIVE_ZLIB=1,
+                           MOZ_SYSTEM_ZLIB=1,
                            AC_MSG_ERROR([Insufficient zlib version for --with-system-zlib ($MOZZLIB required)]))
         fi
     fi
@@ -49,6 +49,6 @@ fi
 
 AC_SUBST_LIST(MOZ_ZLIB_CFLAGS)
 AC_SUBST_LIST(MOZ_ZLIB_LIBS)
-AC_SUBST(MOZ_NATIVE_ZLIB)
+AC_SUBST(MOZ_SYSTEM_ZLIB)
 
 ])
diff --git a/config/Makefile.in b/config/Makefile.in
index 5055cdf70683..07067d70181a 100644
--- a/config/Makefile.in
+++ b/config/Makefile.in
@@ -41,14 +41,14 @@ export:: $(export-preqs)
 	$(PYTHON) -m mozbuild.action.preprocessor $(DEFINES) $(ACDEFINES) \
 		-DMOZ_TREE_CAIRO=$(MOZ_TREE_CAIRO) \
 		-DMOZ_TREE_PIXMAN=$(MOZ_TREE_PIXMAN) \
-		-DMOZ_NATIVE_HUNSPELL=$(MOZ_NATIVE_HUNSPELL) \
-		-DMOZ_NATIVE_BZ2=$(MOZ_NATIVE_BZ2) \
-		-DMOZ_NATIVE_ZLIB=$(MOZ_NATIVE_ZLIB) \
-		-DMOZ_NATIVE_PNG=$(MOZ_NATIVE_PNG) \
-		-DMOZ_NATIVE_JPEG=$(MOZ_NATIVE_JPEG) \
-		-DMOZ_NATIVE_LIBEVENT=$(MOZ_NATIVE_LIBEVENT) \
-		-DMOZ_NATIVE_LIBVPX=$(MOZ_NATIVE_LIBVPX) \
-		-DMOZ_NATIVE_ICU=$(MOZ_NATIVE_ICU) \
+		-DMOZ_SYSTEM_HUNSPELL=$(MOZ_SYSTEM_HUNSPELL) \
+		-DMOZ_SYSTEM_BZ2=$(MOZ_SYSTEM_BZ2) \
+		-DMOZ_SYSTEM_ZLIB=$(MOZ_SYSTEM_ZLIB) \
+		-DMOZ_SYSTEM_PNG=$(MOZ_SYSTEM_PNG) \
+		-DMOZ_SYSTEM_JPEG=$(MOZ_SYSTEM_JPEG) \
+		-DMOZ_SYSTEM_LIBEVENT=$(MOZ_SYSTEM_LIBEVENT) \
+		-DMOZ_SYSTEM_LIBVPX=$(MOZ_SYSTEM_LIBVPX) \
+		-DMOZ_SYSTEM_ICU=$(MOZ_SYSTEM_ICU) \
 		$(srcdir)/system-headers | $(PERL) $(topsrcdir)/nsprpub/config/make-system-wrappers.pl system_wrappers
 	$(INSTALL) system_wrappers $(DIST)
 
diff --git a/config/external/ffi/Makefile.in b/config/external/ffi/Makefile.in
index 19e80d8761f9..c268c5f31d8a 100644
--- a/config/external/ffi/Makefile.in
+++ b/config/external/ffi/Makefile.in
@@ -2,7 +2,7 @@
 # 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/.
 
-ifndef MOZ_NATIVE_FFI
+ifndef MOZ_SYSTEM_FFI
 
 include $(topsrcdir)/config/config.mk
 
diff --git a/config/external/ffi/moz.build b/config/external/ffi/moz.build
index 725b483153f9..2ee6995932f8 100644
--- a/config/external/ffi/moz.build
+++ b/config/external/ffi/moz.build
@@ -6,7 +6,7 @@
 
 Library('ffi')
 
-if CONFIG['MOZ_NATIVE_FFI']:
+if CONFIG['MOZ_SYSTEM_FFI']:
     OS_LIBS += CONFIG['MOZ_FFI_LIBS']
 else:
     if CONFIG['_MSC_VER']:
diff --git a/config/external/icu/Makefile.in b/config/external/icu/Makefile.in
index 7781b23712a9..e54c855047fa 100644
--- a/config/external/icu/Makefile.in
+++ b/config/external/icu/Makefile.in
@@ -4,7 +4,7 @@
 
 # Ensure that this happens before including rules.mk
 ifdef USE_ICU
-  ifndef MOZ_NATIVE_ICU
+  ifndef MOZ_SYSTEM_ICU
   # Library names: On Windows, ICU uses modified library names for static
   # and debug libraries.
     ifdef MOZ_SHARED_ICU
@@ -29,13 +29,13 @@ ifdef USE_ICU
                              cp -p $(DEPTH)/intl/icu/target/lib/s$(libname)$(MOZ_ICU_DBG_SUFFIX).lib $(DEPTH)/intl/icu/target/lib/$(libname)$(MOZ_ICU_DBG_SUFFIX).lib;)
       endif
     endif # MOZ_SHARED_ICU
-  endif # !MOZ_NATIVE_ICU
+  endif # !MOZ_SYSTEM_ICU
 endif # USE_ICU
 
 include $(topsrcdir)/config/rules.mk
 
 ifdef USE_ICU
-ifndef MOZ_NATIVE_ICU
+ifndef MOZ_SYSTEM_ICU
 target:: buildicu
 $(STATIC_LIBS): buildicu
 
diff --git a/config/external/icu/moz.build b/config/external/icu/moz.build
index ef8a706474c7..49cb5fe965dd 100644
--- a/config/external/icu/moz.build
+++ b/config/external/icu/moz.build
@@ -6,7 +6,7 @@
 
 Library('icu')
 
-if CONFIG['MOZ_NATIVE_ICU']:
+if CONFIG['MOZ_SYSTEM_ICU']:
     OS_LIBS += CONFIG['MOZ_ICU_LIBS']
 else:
     # Order needs to be preserved
diff --git a/config/external/moz.build b/config/external/moz.build
index 40b9036f7360..3861e1ffcdfb 100644
--- a/config/external/moz.build
+++ b/config/external/moz.build
@@ -10,11 +10,11 @@ DIRS += [
     'lgpllibs',
     'sqlite',
 ]
-if not CONFIG['MOZ_NATIVE_JPEG']:
+if not CONFIG['MOZ_SYSTEM_JPEG']:
     external_dirs += ['media/libjpeg']
 
 if CONFIG['MOZ_UPDATER']:
-    if not CONFIG['MOZ_NATIVE_BZ2']:
+    if not CONFIG['MOZ_SYSTEM_BZ2']:
         external_dirs += ['modules/libbz2']
 
 # There's no "native" brotli or woff2 yet, but probably in the future...
@@ -30,10 +30,10 @@ if CONFIG['MOZ_TREMOR']:
 if CONFIG['MOZ_WEBM_ENCODER']:
     external_dirs += ['media/libmkv']
 
-if not CONFIG['MOZ_NATIVE_LIBVPX']:
+if not CONFIG['MOZ_SYSTEM_LIBVPX']:
     external_dirs += ['media/libvpx']
 
-if not CONFIG['MOZ_NATIVE_PNG']:
+if not CONFIG['MOZ_SYSTEM_PNG']:
     external_dirs += ['media/libpng']
 
 if CONFIG['CPU_ARCH'] == 'arm':
diff --git a/config/external/nss/Makefile.in b/config/external/nss/Makefile.in
index 99546d8cc570..be10a3d3b165 100644
--- a/config/external/nss/Makefile.in
+++ b/config/external/nss/Makefile.in
@@ -3,7 +3,7 @@
 # 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/.
 
-ifndef MOZ_NATIVE_NSS
+ifndef MOZ_SYSTEM_NSS
 
 CC_WRAPPER =
 CXX_WRAPPER =
@@ -119,7 +119,7 @@ DEFAULT_GMAKE_FLAGS += NSS_ENABLE_ECC=1
 ifeq ($(OS_ARCH)_$(GNU_CC),WINNT_1)
 DEFAULT_GMAKE_FLAGS += OS_DLLFLAGS='-static-libgcc' NSPR31_LIB_PREFIX=lib
 endif
-ifndef MOZ_NATIVE_SQLITE
+ifndef MOZ_SYSTEM_SQLITE
 ifdef MOZ_FOLD_LIBS
 DEFAULT_GMAKE_FLAGS += SQLITE_LIB_NAME=nss3
 else
diff --git a/config/external/nss/crmf/moz.build b/config/external/nss/crmf/moz.build
index 9b8005f96e2b..a9cae31e38e9 100644
--- a/config/external/nss/crmf/moz.build
+++ b/config/external/nss/crmf/moz.build
@@ -6,7 +6,7 @@
 
 Library('crmf')
 
-if CONFIG['MOZ_NATIVE_NSS']:
+if CONFIG['MOZ_SYSTEM_NSS']:
     OS_LIBS += [l for l in CONFIG['NSS_LIBS'] if l.startswith('-L')]
     OS_LIBS += ['-lcrmf']
 else:
diff --git a/config/external/nss/moz.build b/config/external/nss/moz.build
index 771910f319ae..732272b17c05 100644
--- a/config/external/nss/moz.build
+++ b/config/external/nss/moz.build
@@ -6,7 +6,7 @@
 
 DIRS += ['crmf']
 
-if CONFIG['MOZ_NATIVE_NSS']:
+if CONFIG['MOZ_SYSTEM_NSS']:
     Library('nss')
     OS_LIBS += CONFIG['NSS_LIBS']
 elif CONFIG['MOZ_FOLD_LIBS']:
diff --git a/config/external/sqlite/moz.build b/config/external/sqlite/moz.build
index 97aeba158146..dd1b7e2165a9 100644
--- a/config/external/sqlite/moz.build
+++ b/config/external/sqlite/moz.build
@@ -4,7 +4,7 @@
 # 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/.
 
-if CONFIG['MOZ_NATIVE_SQLITE']:
+if CONFIG['MOZ_SYSTEM_SQLITE']:
     Library('sqlite')
     OS_LIBS += CONFIG['SQLITE_LIBS']
 else:
diff --git a/config/external/zlib/moz.build b/config/external/zlib/moz.build
index f1efe437af31..75ca284ef6d3 100644
--- a/config/external/zlib/moz.build
+++ b/config/external/zlib/moz.build
@@ -6,7 +6,7 @@
 
 Library('zlib')
 
-if CONFIG['MOZ_NATIVE_ZLIB']:
+if CONFIG['MOZ_SYSTEM_ZLIB']:
     OS_LIBS += CONFIG['MOZ_ZLIB_LIBS']
 else:
     if CONFIG['ZLIB_IN_MOZGLUE']:
diff --git a/config/system-headers b/config/system-headers
index 46d82ed441d9..835da777752f 100644
--- a/config/system-headers
+++ b/config/system-headers
@@ -574,7 +574,7 @@ JavaVM/jni.h
 JManager.h
 JNIEnvTests.h
 jni.h
-#if MOZ_NATIVE_JPEG==1
+#if MOZ_SYSTEM_JPEG==1
 jpeglib.h
 #endif
 JVMManagerTests.h
@@ -1263,10 +1263,10 @@ soundtouch/SoundTouchFactory.h
 #if MOZ_LIBAV_FFT==1
 libavcodec/avfft.h
 #endif
-#if MOZ_NATIVE_PNG==1
+#if MOZ_SYSTEM_PNG==1
 png.h
 #endif
-#if MOZ_NATIVE_ZLIB==1
+#if MOZ_SYSTEM_ZLIB==1
 zlib.h
 #endif
 #ifdef MOZ_ENABLE_STARTUP_NOTIFICATION
@@ -1277,16 +1277,16 @@ libsn/sn-launcher.h
 libsn/sn-monitor.h
 libsn/sn-util.h
 #endif
-#if MOZ_NATIVE_HUNSPELL==1
+#if MOZ_SYSTEM_HUNSPELL==1
 hunspell.hxx
 #endif
-#if MOZ_NATIVE_BZ2==1
+#if MOZ_SYSTEM_BZ2==1
 bzlib.h
 #endif
 #ifdef MOZ_ENABLE_GIO
 gio/gio.h
 #endif
-#if MOZ_NATIVE_LIBEVENT==1
+#if MOZ_SYSTEM_LIBEVENT==1
 event.h
 #else
 sys/event.h
@@ -1305,7 +1305,7 @@ QtSparql/qsparqlresult.h
 #if MOZ_TREE_PIXMAN!=1
 pixman.h
 #endif
-#if MOZ_NATIVE_LIBVPX==1
+#if MOZ_SYSTEM_LIBVPX==1
 vpx/svc_context.h
 vpx/vpx_codec.h
 vpx/vpx_decoder.h
diff --git a/extensions/spellcheck/hunspell/moz.build b/extensions/spellcheck/hunspell/moz.build
index 2833fd1a7622..34ee484ec8a8 100644
--- a/extensions/spellcheck/hunspell/moz.build
+++ b/extensions/spellcheck/hunspell/moz.build
@@ -5,7 +5,7 @@
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 DIRS += ['glue']
-if not CONFIG['MOZ_NATIVE_HUNSPELL']:
+if not CONFIG['MOZ_SYSTEM_HUNSPELL']:
     DIRS += ['src']
 
 if CONFIG['ENABLE_TESTS']:
diff --git a/ipc/chromium/moz.build b/ipc/chromium/moz.build
index 88aaafe859a9..264f11e7c803 100644
--- a/ipc/chromium/moz.build
+++ b/ipc/chromium/moz.build
@@ -73,7 +73,7 @@ if os_win:
         'src/chrome/common/process_watcher_win.cc',
         'src/chrome/common/transport_dib_win.cc',
     ]
-elif not CONFIG['MOZ_NATIVE_LIBEVENT']:
+elif not CONFIG['MOZ_SYSTEM_LIBEVENT']:
     DIRS += ['src/third_party']
 
 if os_posix:
diff --git a/ipc/chromium/src/third_party/libeventcommon.mozbuild b/ipc/chromium/src/third_party/libeventcommon.mozbuild
index bb8f41bcf404..0114cd77b0c2 100644
--- a/ipc/chromium/src/third_party/libeventcommon.mozbuild
+++ b/ipc/chromium/src/third_party/libeventcommon.mozbuild
@@ -28,7 +28,7 @@ else:
         else:
             libevent_include_suffix = 'linux'
 
-if os_posix and not CONFIG['MOZ_NATIVE_LIBEVENT']:
+if os_posix and not CONFIG['MOZ_SYSTEM_LIBEVENT']:
     DEFINES['HAVE_CONFIG_H'] = True
     LOCAL_INCLUDES += sorted([
         'libevent',
diff --git a/ipc/chromium/src/third_party/moz.build b/ipc/chromium/src/third_party/moz.build
index 4740c9b6391c..44127fe9d7a2 100644
--- a/ipc/chromium/src/third_party/moz.build
+++ b/ipc/chromium/src/third_party/moz.build
@@ -10,7 +10,7 @@ include(libevent_path_prefix + '/libeventcommon.mozbuild')
 if os_win:
     error('should not reach here on Windows')
 
-if CONFIG['MOZ_NATIVE_LIBEVENT']:
+if CONFIG['MOZ_SYSTEM_LIBEVENT']:
     error('should not reach here if we are using a native libevent')
 
 UNIFIED_SOURCES += [
diff --git a/js/src/moz.build b/js/src/moz.build
index ab1c340fed65..54596d59e0cd 100644
--- a/js/src/moz.build
+++ b/js/src/moz.build
@@ -558,7 +558,7 @@ if CONFIG['JS_HAS_CTYPES']:
         'ctypes/CTypes.cpp',
         'ctypes/Library.cpp',
     ]
-    if not CONFIG['MOZ_NATIVE_FFI']:
+    if not CONFIG['MOZ_SYSTEM_FFI']:
         LOCAL_INCLUDES += [
             '!ctypes/libffi/include',
         ]
@@ -726,7 +726,7 @@ selfhosted.inputs = [
 ]
 
 if CONFIG['JS_HAS_CTYPES']:
-    if CONFIG['MOZ_NATIVE_FFI']:
+    if CONFIG['MOZ_SYSTEM_FFI']:
         CXXFLAGS += CONFIG['MOZ_FFI_CFLAGS']
     else:
         # Windows needs this to be linked with a static library.
diff --git a/js/src/old-configure.in b/js/src/old-configure.in
index 0f1ff0a12d18..4396b4a87979 100644
--- a/js/src/old-configure.in
+++ b/js/src/old-configure.in
@@ -3371,7 +3371,7 @@ HOST_CXXFLAGS=`echo \
     $HOST_CXXFLAGS`
 
 AC_SUBST(_DEPEND_CFLAGS)
-AC_SUBST(MOZ_NATIVE_NSPR)
+AC_SUBST(MOZ_SYSTEM_NSPR)
 
 if test -n "$MOZ_NUWA_PROCESS"; then
     AC_DEFINE(MOZ_NUWA_PROCESS)
diff --git a/media/webrtc/signaling/test/common.build b/media/webrtc/signaling/test/common.build
index c0a624fc1e43..bcf257a52f34 100644
--- a/media/webrtc/signaling/test/common.build
+++ b/media/webrtc/signaling/test/common.build
@@ -105,10 +105,10 @@ OS_LIBS += CONFIG['REALTIME_LIBS']
 if CONFIG['MOZ_ALSA']:
     OS_LIBS += CONFIG['MOZ_ALSA_LIBS']
 
-if CONFIG['MOZ_NATIVE_JPEG']:
+if CONFIG['MOZ_SYSTEM_JPEG']:
     OS_LIBS += CONFIG['MOZ_JPEG_LIBS']
 
-if CONFIG['MOZ_NATIVE_LIBVPX']:
+if CONFIG['MOZ_SYSTEM_LIBVPX']:
     OS_LIBS += CONFIG['MOZ_LIBVPX_LIBS']
 
 if not CONFIG['MOZ_TREE_PIXMAN']:
diff --git a/memory/build/jemalloc_config.cpp b/memory/build/jemalloc_config.cpp
index 94946d26fcff..441fd8a2b998 100644
--- a/memory/build/jemalloc_config.cpp
+++ b/memory/build/jemalloc_config.cpp
@@ -11,7 +11,7 @@
 #include <mozilla/Assertions.h>
 #include "mozilla/Types.h"
 
-#if defined(MOZ_NATIVE_JEMALLOC)
+#if defined(MOZ_SYSTEM_JEMALLOC)
 #include MALLOC_H
 #else
 #define DLLEXPORT
diff --git a/memory/build/moz.build b/memory/build/moz.build
index 3595bc663c79..c2f094ad8544 100644
--- a/memory/build/moz.build
+++ b/memory/build/moz.build
@@ -41,7 +41,7 @@ if CONFIG['MOZ_REPLACE_MALLOC']:
 Library('memory')
 
 if CONFIG['MOZ_JEMALLOC4']:
-    if not CONFIG['MOZ_NATIVE_JEMALLOC']:
+    if not CONFIG['MOZ_SYSTEM_JEMALLOC']:
         USE_LIBS += [
             'jemalloc',
         ]
@@ -56,7 +56,7 @@ if CONFIG['MOZ_GLUE_IN_PROGRAM']:
 
 # Keep jemalloc separated when mozglue is statically linked
 if CONFIG['MOZ_MEMORY'] and (CONFIG['OS_TARGET'] in ('WINNT', 'Darwin', 'Android') or
-                             CONFIG['MOZ_NATIVE_JEMALLOC']):
+                             CONFIG['MOZ_SYSTEM_JEMALLOC']):
     FINAL_LIBRARY = 'mozglue'
 
 if CONFIG['MOZ_REPLACE_MALLOC'] and CONFIG['OS_TARGET'] == 'Darwin':
diff --git a/memory/build/mozjemalloc_compat.c b/memory/build/mozjemalloc_compat.c
index 14489b70ff51..6591892c1372 100644
--- a/memory/build/mozjemalloc_compat.c
+++ b/memory/build/mozjemalloc_compat.c
@@ -14,7 +14,7 @@
 
 #include <stdbool.h>
 
-#if defined(MOZ_NATIVE_JEMALLOC)
+#if defined(MOZ_SYSTEM_JEMALLOC)
 #  include MALLOC_H
 #else
 #  include "jemalloc/jemalloc.h"
diff --git a/memory/build/mozmemory_wrap.h b/memory/build/mozmemory_wrap.h
index 6e8920951876..066d57782dd3 100644
--- a/memory/build/mozmemory_wrap.h
+++ b/memory/build/mozmemory_wrap.h
@@ -125,7 +125,7 @@
 
 #include "mozilla/Types.h"
 
-#if !defined(MOZ_NATIVE_JEMALLOC)
+#if !defined(MOZ_SYSTEM_JEMALLOC)
 #  ifdef MOZ_MEMORY_IMPL
 #    if defined(MOZ_JEMALLOC_IMPL) && defined(MOZ_REPLACE_MALLOC) && !defined(MOZ_REPLACE_JEMALLOC)
 #      define mozmem_malloc_impl(a)     je_ ## a
@@ -157,11 +157,11 @@
 /* All other jemalloc3 functions are prefixed with "je_", except when
  * building against an unprefixed system jemalloc library */
 #  define je_(a) je_ ## a
-#else /* defined(MOZ_NATIVE_JEMALLOC) */
+#else /* defined(MOZ_SYSTEM_JEMALLOC) */
 #  define je_(a) a
 #endif
 
-#if !defined(MOZ_MEMORY_IMPL) || defined(MOZ_NATIVE_JEMALLOC)
+#if !defined(MOZ_MEMORY_IMPL) || defined(MOZ_SYSTEM_JEMALLOC)
 #  define MOZ_MEMORY_API MFBT_API
 #  define MOZ_JEMALLOC_API MFBT_API
 #endif
diff --git a/memory/build/replace_malloc.c b/memory/build/replace_malloc.c
index 06bf26b9bf2a..897d88ffda50 100644
--- a/memory/build/replace_malloc.c
+++ b/memory/build/replace_malloc.c
@@ -10,7 +10,7 @@
 #  error Should not compile this file when replace-malloc is disabled
 #endif
 
-#ifdef MOZ_NATIVE_JEMALLOC
+#ifdef MOZ_SYSTEM_JEMALLOC
 #  error Should not compile this file when we want to use native jemalloc
 #endif
 
diff --git a/memory/moz.build b/memory/moz.build
index 697f12d7277a..7b7fc616f143 100644
--- a/memory/moz.build
+++ b/memory/moz.build
@@ -19,7 +19,7 @@ if CONFIG['MOZ_MEMORY']:
     ]
 
     if CONFIG['MOZ_JEMALLOC4'] or CONFIG['MOZ_REPLACE_MALLOC']:
-        if not CONFIG['MOZ_NATIVE_JEMALLOC']:
+        if not CONFIG['MOZ_SYSTEM_JEMALLOC']:
             DIRS += ['jemalloc']
 
     if CONFIG['MOZ_REPLACE_MALLOC']:
diff --git a/mozglue/build/moz.build b/mozglue/build/moz.build
index 58e2db6be140..1c6f660050c5 100644
--- a/mozglue/build/moz.build
+++ b/mozglue/build/moz.build
@@ -33,7 +33,7 @@ if CONFIG['OS_TARGET'] == 'WINNT':
 
 if not CONFIG['JS_STANDALONE']:
 
-    if CONFIG['MOZ_MEMORY'] and (CONFIG['MOZ_NATIVE_JEMALLOC'] or FORCE_SHARED_LIB):
+    if CONFIG['MOZ_MEMORY'] and (CONFIG['MOZ_SYSTEM_JEMALLOC'] or FORCE_SHARED_LIB):
         pass
         # TODO: SHARED_LIBRARY_LIBS go here
     else:
diff --git a/old-configure.in b/old-configure.in
index d951cd5beb12..5bdee2ef9c0b 100644
--- a/old-configure.in
+++ b/old-configure.in
@@ -3264,12 +3264,12 @@ _SAVE_LDFLAGS=$LDFLAGS
 _SAVE_LIBS=$LIBS
 if test "$LIBEVENT_DIR" = yes; then
     PKG_CHECK_MODULES(MOZ_LIBEVENT, libevent,
-        MOZ_NATIVE_LIBEVENT=1,
+        MOZ_SYSTEM_LIBEVENT=1,
         LIBEVENT_DIR=/usr)
 fi
 if test -z "$LIBEVENT_DIR" -o "$LIBEVENT_DIR" = no; then
-    MOZ_NATIVE_LIBEVENT=
-elif test -z "$MOZ_NATIVE_LIBEVENT"; then
+    MOZ_SYSTEM_LIBEVENT=
+elif test -z "$MOZ_SYSTEM_LIBEVENT"; then
     CFLAGS="-I${LIBEVENT_DIR}/include $CFLAGS"
     LDFLAGS="-L${LIBEVENT_DIR}/lib $LDFLAGS"
     MOZ_CHECK_HEADER(event.h,
@@ -3278,16 +3278,16 @@ elif test -z "$MOZ_NATIVE_LIBEVENT"; then
          fi],
         AC_MSG_ERROR([--with-system-libevent requested but event.h not found]))
     AC_CHECK_LIB(event, event_init,
-                 [MOZ_NATIVE_LIBEVENT=1
+                 [MOZ_SYSTEM_LIBEVENT=1
                   MOZ_LIBEVENT_CFLAGS="-I${LIBEVENT_DIR}/include"
                   MOZ_LIBEVENT_LIBS="-L${LIBEVENT_DIR}/lib -levent"],
-                 [MOZ_NATIVE_LIBEVENT= MOZ_LIBEVENT_CFLAGS= MOZ_LIBEVENT_LIBS=])
+                 [MOZ_SYSTEM_LIBEVENT= MOZ_LIBEVENT_CFLAGS= MOZ_LIBEVENT_LIBS=])
 fi
 CFLAGS=$_SAVE_CFLAGS
 LDFLAGS=$_SAVE_LDFLAGS
 LIBS=$_SAVE_LIBS
 
-AC_SUBST(MOZ_NATIVE_LIBEVENT)
+AC_SUBST(MOZ_SYSTEM_LIBEVENT)
 
 dnl ========================================================
 dnl = If NSS was not detected in the system,
@@ -3299,10 +3299,10 @@ MOZ_ARG_WITH_BOOL(system-nss,
     _USE_SYSTEM_NSS=1 )
 
 if test -n "$_USE_SYSTEM_NSS"; then
-    AM_PATH_NSS(3.23, [MOZ_NATIVE_NSS=1], [AC_MSG_ERROR([you don't have NSS installed or your version is too old])])
+    AM_PATH_NSS(3.23, [MOZ_SYSTEM_NSS=1], [AC_MSG_ERROR([you don't have NSS installed or your version is too old])])
 fi
 
-if test -n "$MOZ_NATIVE_NSS"; then
+if test -n "$MOZ_SYSTEM_NSS"; then
    NSS_LIBS="$NSS_LIBS -lcrmf"
 else
    NSS_CFLAGS="-I${DIST}/include/nss"
@@ -3377,12 +3377,12 @@ if test -n "${JPEG_DIR}" -a "${JPEG_DIR}" != "yes"; then
     LDFLAGS="-L${JPEG_DIR}/lib $LDFLAGS"
 fi
 if test -z "$JPEG_DIR" -o "$JPEG_DIR" = no; then
-    MOZ_NATIVE_JPEG=
+    MOZ_SYSTEM_JPEG=
 else
-    AC_CHECK_LIB(jpeg, jpeg_destroy_compress, [MOZ_NATIVE_JPEG=1 MOZ_JPEG_LIBS="-ljpeg"], MOZ_NATIVE_JPEG=)
+    AC_CHECK_LIB(jpeg, jpeg_destroy_compress, [MOZ_SYSTEM_JPEG=1 MOZ_JPEG_LIBS="-ljpeg"], MOZ_SYSTEM_JPEG=)
 fi
 
-if test "$MOZ_NATIVE_JPEG" = 1; then
+if test "$MOZ_SYSTEM_JPEG" = 1; then
     AC_TRY_COMPILE([ #include <stdio.h>
                      #include <sys/types.h>
                      #include <jpeglib.h> ],
@@ -3393,14 +3393,14 @@ if test "$MOZ_NATIVE_JPEG" = 1; then
                      #error "libjpeg-turbo JCS_EXTENSIONS required"
                      #endif
                      ],
-                   MOZ_NATIVE_JPEG=1,
+                   MOZ_SYSTEM_JPEG=1,
                    AC_MSG_ERROR([Insufficient JPEG library version for --with-system-jpeg]))
 fi
 CFLAGS=$_SAVE_CFLAGS
 LDFLAGS=$_SAVE_LDFLAGS
 LIBS=$_SAVE_LIBS
 
-if test -n "${JPEG_DIR}" -a -d "${JPEG_DIR}" -a "$MOZ_NATIVE_JPEG" = 1; then
+if test -n "${JPEG_DIR}" -a -d "${JPEG_DIR}" -a "$MOZ_SYSTEM_JPEG" = 1; then
     MOZ_JPEG_CFLAGS="-I${JPEG_DIR}/include"
     MOZ_JPEG_LIBS="-L${JPEG_DIR}/lib ${MOZ_JPEG_LIBS}"
 fi
@@ -3410,7 +3410,7 @@ dnl system ZLIB support
 dnl ========================================================
 MOZ_ZLIB_CHECK([1.2.3])
 
-if test "$MOZ_LINKER" = 1 -a "$MOZ_NATIVE_ZLIB" != 1; then
+if test "$MOZ_LINKER" = 1 -a "$MOZ_SYSTEM_ZLIB" != 1; then
     AC_MSG_ERROR([Custom dynamic linker requires --with-system-zlib])
 fi
 
@@ -3432,16 +3432,16 @@ if test -n "${BZ2_DIR}" -a "${BZ2_DIR}" != "yes"; then
     LDFLAGS="-L${BZ2_DIR}/lib $LDFLAGS"
 fi
 if test -z "$BZ2_DIR" -o "$BZ2_DIR" = no; then
-    MOZ_NATIVE_BZ2=
+    MOZ_SYSTEM_BZ2=
 else
-    AC_CHECK_LIB(bz2, BZ2_bzread, [MOZ_NATIVE_BZ2=1 MOZ_BZ2_LIBS="-lbz2"],
-    [MOZ_NATIVE_BZ2= MOZ_BZ2_CFLAGS= MOZ_BZ2_LIBS=])
+    AC_CHECK_LIB(bz2, BZ2_bzread, [MOZ_SYSTEM_BZ2=1 MOZ_BZ2_LIBS="-lbz2"],
+    [MOZ_SYSTEM_BZ2= MOZ_BZ2_CFLAGS= MOZ_BZ2_LIBS=])
 fi
 CFLAGS=$_SAVE_CFLAGS
 LDFLAGS=$_SAVE_LDFLAGS
 LIBS=$_SAVE_LIBS
 
-if test "${BZ2_DIR}" -a -d "${BZ2_DIR}" -a "$MOZ_NATIVE_BZ2" = 1; then
+if test "${BZ2_DIR}" -a -d "${BZ2_DIR}" -a "$MOZ_SYSTEM_BZ2" = 1; then
     MOZ_BZ2_CFLAGS="-I${BZ2_DIR}/include"
     MOZ_BZ2_LIBS="-L${BZ2_DIR}/lib ${MOZ_BZ2_LIBS}"
 fi
@@ -3462,14 +3462,14 @@ if test -n "${PNG_DIR}" -a "${PNG_DIR}" != "yes"; then
     LDFLAGS="-L${PNG_DIR}/lib $LDFLAGS"
 fi
 if test -z "$PNG_DIR" -o "$PNG_DIR" = no; then
-    MOZ_NATIVE_PNG=
+    MOZ_SYSTEM_PNG=
 else
-    AC_CHECK_LIB(png, png_get_valid, [MOZ_NATIVE_PNG=1 MOZ_PNG_LIBS="-lpng"],
+    AC_CHECK_LIB(png, png_get_valid, [MOZ_SYSTEM_PNG=1 MOZ_PNG_LIBS="-lpng"],
                  AC_MSG_ERROR([--with-system-png requested but no working libpng found]))
     AC_CHECK_LIB(png, png_get_acTL, ,
                  AC_MSG_ERROR([--with-system-png won't work because the system's libpng doesn't have APNG support]))
 fi
-if test "$MOZ_NATIVE_PNG" = 1; then
+if test "$MOZ_SYSTEM_PNG" = 1; then
     AC_TRY_COMPILE([ #include <stdio.h>
                      #include <sys/types.h>
                      #include <png.h> ],
@@ -3479,20 +3479,20 @@ if test "$MOZ_NATIVE_PNG" = 1; then
                      #ifndef PNG_UINT_31_MAX
                      #error "Insufficient libpng version."
                      #endif ],
-                   MOZ_NATIVE_PNG=1,
+                   MOZ_SYSTEM_PNG=1,
                    AC_MSG_ERROR([--with-system-png requested but no working libpng found]))
 fi
 CFLAGS=$_SAVE_CFLAGS
 LDFLAGS=$_SAVE_LDFLAGS
 LIBS=$_SAVE_LIBS
 
-if test "${PNG_DIR}" -a -d "${PNG_DIR}" -a "$MOZ_NATIVE_PNG" = 1; then
+if test "${PNG_DIR}" -a -d "${PNG_DIR}" -a "$MOZ_SYSTEM_PNG" = 1; then
     MOZ_PNG_CFLAGS="-I${PNG_DIR}/include"
     MOZ_PNG_LIBS="-L${PNG_DIR}/lib ${MOZ_PNG_LIBS}"
 fi
 
 MOZ_PNG_ARM_NEON_CHECK=
-if test "$MOZ_NATIVE_PNG" != 1 -a "$CPU_ARCH" = "arm" ; then
+if test "$MOZ_SYSTEM_PNG" != 1 -a "$CPU_ARCH" = "arm" ; then
     MOZ_ARG_ENABLE_STRING(png-arm-neon-support,
         [  --enable-png-arm-neon-support=TYPE
              Options include:
@@ -3527,13 +3527,13 @@ dnl ========================================================
 MOZ_ARG_ENABLE_BOOL(system-hunspell,
 [  --enable-system-hunspell
                           Use system hunspell (located with pkgconfig)],
-    MOZ_NATIVE_HUNSPELL=1 )
+    MOZ_SYSTEM_HUNSPELL=1 )
 
-if test -n "$MOZ_NATIVE_HUNSPELL"; then
+if test -n "$MOZ_SYSTEM_HUNSPELL"; then
     PKG_CHECK_MODULES(MOZ_HUNSPELL, hunspell)
 fi
 
-AC_SUBST(MOZ_NATIVE_HUNSPELL)
+AC_SUBST(MOZ_SYSTEM_HUNSPELL)
 
 dnl ========================================================
 dnl system libffi Support
@@ -5216,7 +5216,7 @@ dnl system libvpx Support
 dnl ========================================================
 MOZ_ARG_WITH_BOOL(system-libvpx,
 [  --with-system-libvpx    Use system libvpx (located with pkgconfig)],
-    MOZ_NATIVE_LIBVPX=1)
+    MOZ_SYSTEM_LIBVPX=1)
 
 MOZ_LIBVPX_CFLAGS=
 MOZ_LIBVPX_LIBS=
@@ -5227,7 +5227,7 @@ fi
 
 _SAVE_CFLAGS=$CFLAGS
 _SAVE_LIBS=$LIBS
-if test -n "$MOZ_NATIVE_LIBVPX"; then
+if test -n "$MOZ_SYSTEM_LIBVPX"; then
     dnl ============================
     dnl === libvpx Version check ===
     dnl ============================
@@ -5253,7 +5253,7 @@ fi
 CFLAGS=$_SAVE_CFLAGS
 LIBS=$_SAVE_LIBS
 
-AC_SUBST(MOZ_NATIVE_LIBVPX)
+AC_SUBST(MOZ_SYSTEM_LIBVPX)
 AC_SUBST_LIST(MOZ_LIBVPX_CFLAGS)
 AC_SUBST_LIST(MOZ_LIBVPX_LIBS)
 
@@ -5263,7 +5263,7 @@ else
     MOZ_TREMOR=1
 fi
 
-if test -z "$MOZ_NATIVE_LIBVPX"; then
+if test -z "$MOZ_SYSTEM_LIBVPX"; then
 
     dnl Detect if we can use an assembler to compile optimized assembly for libvpx.
     dnl We currently require yasm on all x86 platforms and require yasm 1.1.0 on Win32.
@@ -5883,7 +5883,7 @@ dnl = libjpeg-turbo configuration
 dnl ========================================================
 MOZ_LIBJPEG_TURBO=
 LIBJPEG_TURBO_USE_YASM=
-if test -z "$MOZ_NATIVE_JPEG"; then
+if test -z "$MOZ_SYSTEM_JPEG"; then
     MOZ_LIBJPEG_TURBO=1
 fi
 
@@ -5892,7 +5892,7 @@ MOZ_ARG_DISABLE_BOOL(libjpeg_turbo,
     MOZ_LIBJPEG_TURBO=,
     MOZ_LIBJPEG_TURBO=1)
 
-if test "$MOZ_NATIVE_JPEG" = 1 -a "$MOZ_LIBJPEG_TURBO" = 1; then
+if test "$MOZ_SYSTEM_JPEG" = 1 -a "$MOZ_LIBJPEG_TURBO" = 1; then
     AC_MSG_ERROR([cannot use --with-system-jpeg with --enable-libjpeg-turbo.])
 fi
 
@@ -6449,13 +6449,13 @@ dnl ========================================================
 dnl Check for sqlite
 dnl ========================================================
 
-MOZ_NATIVE_SQLITE=
+MOZ_SYSTEM_SQLITE=
 MOZ_ARG_ENABLE_BOOL(system-sqlite,
 [  --enable-system-sqlite  Use system sqlite (located with pkgconfig)],
-MOZ_NATIVE_SQLITE=1,
-MOZ_NATIVE_SQLITE= )
+MOZ_SYSTEM_SQLITE=1,
+MOZ_SYSTEM_SQLITE= )
 
-if test -n "$MOZ_NATIVE_SQLITE"
+if test -n "$MOZ_SYSTEM_SQLITE"
 then
     dnl ============================
     dnl === SQLite Version check ===
@@ -6609,10 +6609,10 @@ then
     fi
 fi
 
-if test -n "$MOZ_NATIVE_SQLITE"; then
-    AC_DEFINE(MOZ_NATIVE_SQLITE)
+if test -n "$MOZ_SYSTEM_SQLITE"; then
+    AC_DEFINE(MOZ_SYSTEM_SQLITE)
 fi
-AC_SUBST(MOZ_NATIVE_SQLITE)
+AC_SUBST(MOZ_SYSTEM_SQLITE)
 
 dnl ========================================================
 dnl = Enable help viewer (off by default)
@@ -6902,7 +6902,7 @@ if test -n "$MOZ_REPLACE_MALLOC" -a -z "$MOZ_MEMORY"; then
     AC_MSG_ERROR([--enable-replace-malloc requires --enable-jemalloc])
 elif test -n "$MOZ_REPLACE_MALLOC"; then
     AC_DEFINE(MOZ_REPLACE_MALLOC)
-    MOZ_NATIVE_JEMALLOC=
+    MOZ_SYSTEM_JEMALLOC=
 
     dnl Replace-malloc Mac linkage quirks
     if test -n "$MACOSX_DEPLOYMENT_TARGET"; then
@@ -6964,15 +6964,15 @@ dnl = Jemalloc build setup
 dnl ========================================================
 if test -z "$MOZ_MEMORY"; then
   if test -n "$MOZ_JEMALLOC4" -a -z "$MOZ_REPLACE_MALLOC"; then
-    MOZ_NATIVE_JEMALLOC=1
+    MOZ_SYSTEM_JEMALLOC=1
     AC_CHECK_FUNCS(mallctl nallocx,,
-      [MOZ_NATIVE_JEMALLOC=
+      [MOZ_SYSTEM_JEMALLOC=
        break])
-    if test -n "$MOZ_NATIVE_JEMALLOC"; then
+    if test -n "$MOZ_SYSTEM_JEMALLOC"; then
       MOZ_MEMORY=1
       AC_DEFINE(MOZ_MEMORY)
       AC_DEFINE(MOZ_JEMALLOC4)
-      AC_DEFINE(MOZ_NATIVE_JEMALLOC)
+      AC_DEFINE(MOZ_SYSTEM_JEMALLOC)
     fi
   fi
   case "${target}" in
@@ -7037,7 +7037,7 @@ else
 fi # MOZ_MEMORY
 AC_SUBST(MOZ_MEMORY)
 AC_SUBST(MOZ_JEMALLOC4)
-AC_SUBST(MOZ_NATIVE_JEMALLOC)
+AC_SUBST(MOZ_SYSTEM_JEMALLOC)
 AC_SUBST(MOZ_CRT)
 export MOZ_CRT
 AC_SUBST(MOZ_GLUE_IN_PROGRAM)
@@ -7751,7 +7751,7 @@ dnl =
 dnl ========================================================
 MOZ_ARG_HEADER(Static build options)
 
-if test -z "$MOZ_NATIVE_ZLIB"; then
+if test -z "$MOZ_SYSTEM_ZLIB"; then
 if test -n "$JS_SHARED_LIBRARY"; then
   ZLIB_IN_MOZGLUE=1
   AC_DEFINE(ZLIB_IN_MOZGLUE)
@@ -8595,9 +8595,9 @@ HOST_CXXFLAGS=`echo \
     $HOST_CXXFLAGS`
 
 AC_SUBST(_DEPEND_CFLAGS)
-AC_SUBST(MOZ_NATIVE_JPEG)
-AC_SUBST(MOZ_NATIVE_PNG)
-AC_SUBST(MOZ_NATIVE_BZ2)
+AC_SUBST(MOZ_SYSTEM_JPEG)
+AC_SUBST(MOZ_SYSTEM_PNG)
+AC_SUBST(MOZ_SYSTEM_BZ2)
 
 AC_SUBST_LIST(MOZ_JPEG_CFLAGS)
 AC_SUBST_LIST(MOZ_JPEG_LIBS)
@@ -8620,9 +8620,9 @@ if test "$MOZ_WIDGET_TOOLKIT" = gonk -a -n "$MOZ_B2G_LOADER"; then
 fi
 AC_SUBST(MOZ_B2G_LOADER)
 
-AC_SUBST(MOZ_NATIVE_NSPR)
+AC_SUBST(MOZ_SYSTEM_NSPR)
 
-AC_SUBST(MOZ_NATIVE_NSS)
+AC_SUBST(MOZ_SYSTEM_NSS)
 AC_SUBST(NSS_DISABLE_DBM)
 
 HOST_CMFLAGS=-fobjc-exceptions
@@ -8920,7 +8920,7 @@ if test "$MOZ_TREE_FREETYPE"; then
    export LDFLAGS="$LDFLAGS $MOZ_DEBUG_LDFLAGS"
    # Spaces in the *_CFLAGS and *_LIBS variables are intentionally placed
    # to force freetype to use our settings rather than autodetecting
-   if test -n "$MOZ_NATIVE_PNG"; then
+   if test -n "$MOZ_SYSTEM_PNG"; then
      export LIBPNG_CFLAGS="$MOZ_PNG_CFLAGS "
    else
      export LIBPNG_CFLAGS="-I$_objdir/dist/include"
@@ -9020,7 +9020,7 @@ fi
 if test -n "$ZLIB_IN_MOZGLUE"; then
    MOZ_ZLIB_LIBS=
 fi
-export MOZ_NATIVE_ZLIB
+export MOZ_SYSTEM_ZLIB
 export MOZ_ZLIB_CFLAGS
 export MOZ_ZLIB_LIBS
 export MOZ_APP_NAME
diff --git a/other-licenses/bsdiff/moz.build b/other-licenses/bsdiff/moz.build
index 3848e6af19fe..450596d4eb64 100644
--- a/other-licenses/bsdiff/moz.build
+++ b/other-licenses/bsdiff/moz.build
@@ -10,7 +10,7 @@ HOST_SOURCES += [
 
 HostProgram('mbsdiff')
 
-if CONFIG['MOZ_NATIVE_BZ2']:
+if CONFIG['MOZ_SYSTEM_BZ2']:
     HOST_OS_LIBS += CONFIG['MOZ_BZ2_LIBS']
 else:
     HOST_USE_LIBS += [
diff --git a/services/crypto/modules/WeaveCrypto.js b/services/crypto/modules/WeaveCrypto.js
index fe80cc3297c7..fd88fb64586b 100644
--- a/services/crypto/modules/WeaveCrypto.js
+++ b/services/crypto/modules/WeaveCrypto.js
@@ -131,7 +131,7 @@ WeaveCrypto.prototype = {
 
         // XXX really want to be able to pass specific dlopen flags here.
         var nsslib;
-        if (AppConstants.MOZ_NATIVE_NSS) {
+        if (AppConstants.MOZ_SYSTEM_NSS) {
             // Search platform-dependent library paths for system NSS.
             this.log("Trying NSS library without path");
             nsslib = ctypes.open(path);
diff --git a/storage/SQLiteMutex.h b/storage/SQLiteMutex.h
index a74f3c2dc9a4..a38525fd6d0c 100644
--- a/storage/SQLiteMutex.h
+++ b/storage/SQLiteMutex.h
@@ -50,7 +50,7 @@ public:
     mMutex = aMutex;
   }
 
-#if !defined(DEBUG) || defined(MOZ_NATIVE_SQLITE)
+#if !defined(DEBUG) || defined(MOZ_SYSTEM_SQLITE)
   /**
    * Acquires the mutex.
    */
diff --git a/storage/moz.build b/storage/moz.build
index 0275017903a0..65b7a0c570ba 100644
--- a/storage/moz.build
+++ b/storage/moz.build
@@ -98,8 +98,8 @@ FINAL_LIBRARY = 'xul'
 # Note: On Windows our sqlite build assumes we use jemalloc.  If you disable
 # MOZ_STORAGE_MEMORY on Windows, you will also need to change the "ifdef
 # MOZ_MEMORY" options in db/sqlite3/src/Makefile.in.
-if CONFIG['MOZ_MEMORY'] and (not CONFIG['MOZ_NATIVE_SQLITE']
-                             or CONFIG['MOZ_NATIVE_JEMALLOC']):
+if CONFIG['MOZ_MEMORY'] and (not CONFIG['MOZ_SYSTEM_SQLITE']
+                             or CONFIG['MOZ_SYSTEM_JEMALLOC']):
     if CONFIG['OS_TARGET'] != 'Android':
         DEFINES['MOZ_STORAGE_MEMORY'] = True
 
diff --git a/toolkit/library/moz.build b/toolkit/library/moz.build
index a678f59f03d2..4787e395f6f6 100644
--- a/toolkit/library/moz.build
+++ b/toolkit/library/moz.build
@@ -214,19 +214,19 @@ OS_LIBS += CONFIG['MOZ_CAIRO_OSLIBS']
 OS_LIBS += CONFIG['MOZ_WEBRTC_X11_LIBS']
 OS_LIBS += CONFIG['MOZ_SERVO_LIBS']
 
-if CONFIG['MOZ_NATIVE_JPEG']:
+if CONFIG['MOZ_SYSTEM_JPEG']:
     OS_LIBS += CONFIG['MOZ_JPEG_LIBS']
 
-if CONFIG['MOZ_NATIVE_PNG']:
+if CONFIG['MOZ_SYSTEM_PNG']:
     OS_LIBS += CONFIG['MOZ_PNG_LIBS']
 
-if CONFIG['MOZ_NATIVE_HUNSPELL']:
+if CONFIG['MOZ_SYSTEM_HUNSPELL']:
     OS_LIBS += CONFIG['MOZ_HUNSPELL_LIBS']
 
-if CONFIG['MOZ_NATIVE_LIBEVENT']:
+if CONFIG['MOZ_SYSTEM_LIBEVENT']:
     OS_LIBS += CONFIG['MOZ_LIBEVENT_LIBS']
 
-if CONFIG['MOZ_NATIVE_LIBVPX']:
+if CONFIG['MOZ_SYSTEM_LIBVPX']:
     OS_LIBS += CONFIG['MOZ_LIBVPX_LIBS']
 
 if not CONFIG['MOZ_TREE_PIXMAN']:
diff --git a/toolkit/modules/AppConstants.jsm b/toolkit/modules/AppConstants.jsm
index aea4c2b12ff4..5385ffcb1d41 100644
--- a/toolkit/modules/AppConstants.jsm
+++ b/toolkit/modules/AppConstants.jsm
@@ -234,8 +234,8 @@ this.AppConstants = Object.freeze({
   false,
 #endif
 
-  MOZ_NATIVE_NSS:
-#ifdef MOZ_NATIVE_NSS
+  MOZ_SYSTEM_NSS:
+#ifdef MOZ_SYSTEM_NSS
   true,
 #else
   false,
diff --git a/toolkit/modules/moz.build b/toolkit/modules/moz.build
index 349aa292b2fd..26b2c10a0726 100644
--- a/toolkit/modules/moz.build
+++ b/toolkit/modules/moz.build
@@ -123,7 +123,7 @@ for var in ('ANDROID_PACKAGE_NAME',
 
 for var in ('MOZ_TOOLKIT_SEARCH',
             'MOZ_REQUIRE_SIGNING',
-            'MOZ_NATIVE_NSS',
+            'MOZ_SYSTEM_NSS',
             'MOZ_UPDATER'):
     if CONFIG[var]:
         DEFINES[var] = True
diff --git a/toolkit/mozapps/installer/upload-files.mk b/toolkit/mozapps/installer/upload-files.mk
index 664480973146..facdccda125f 100644
--- a/toolkit/mozapps/installer/upload-files.mk
+++ b/toolkit/mozapps/installer/upload-files.mk
@@ -62,7 +62,7 @@ JSSHELL_BINS  = \
   js$(BIN_SUFFIX) \
   $(DLL_PREFIX)mozglue$(DLL_SUFFIX) \
   $(NULL)
-ifndef MOZ_NATIVE_NSPR
+ifndef MOZ_SYSTEM_NSPR
 ifdef MSVC_C_RUNTIME_DLL
 JSSHELL_BINS += $(MSVC_C_RUNTIME_DLL)
 endif
@@ -78,7 +78,7 @@ JSSHELL_BINS += \
   $(DLL_PREFIX)plc4$(DLL_SUFFIX) \
   $(NULL)
 endif # MOZ_FOLD_LIBS
-endif # MOZ_NATIVE_NSPR
+endif # MOZ_SYSTEM_NSPR
 ifdef MOZ_SHARED_ICU
 ifeq ($(OS_TARGET), WINNT)
 JSSHELL_BINS += \
diff --git a/toolkit/mozapps/update/updater/updater-common.build b/toolkit/mozapps/update/updater/updater-common.build
index a39d47d88019..f4b40ccae9c1 100644
--- a/toolkit/mozapps/update/updater/updater-common.build
+++ b/toolkit/mozapps/update/updater/updater-common.build
@@ -60,7 +60,7 @@ USE_LIBS += [
     'mar',
 ]
 
-if CONFIG['MOZ_NATIVE_BZ2']:
+if CONFIG['MOZ_SYSTEM_BZ2']:
     OS_LIBS += CONFIG['MOZ_BZ2_LIBS']
 else:
     USE_LIBS += [