--- a/embedding/Makefile.in
+++ b/embedding/Makefile.in
@@ -8,22 +8,13 @@ topsrcdir	= @top_srcdir@
 srcdir		= @srcdir@
 VPATH		= @srcdir@
 relativesrcdir = @relativesrcdir@
 
 include $(DEPTH)/config/autoconf.mk
 
 MODULE       = embed
 
-DIRS = base components browser
-
-TEST_DIRS += test
 ifdef ENABLE_TESTS
 XPCSHELL_TESTS = tests/unit
 endif
 
-ifeq ($(MOZ_WIDGET_TOOLKIT),android)
-ifneq (,$(filter mobile/xul b2g,$(MOZ_BUILD_APP)))
-DIRS += android
-endif
-endif
-
 include $(topsrcdir)/config/rules.mk

--- a/embedding/android/Makefile.in
+++ b/embedding/android/Makefile.in
@@ -5,18 +5,16 @@
 DEPTH		= @DEPTH@
 topsrcdir	= @top_srcdir@
 srcdir		= @srcdir@
 VPATH		= @srcdir@
 
 include $(DEPTH)/config/autoconf.mk
 include $(topsrcdir)/ipc/app/defs.mk
 
-DIRS = locales
-
 JAVAFILES = \
   GeckoApp.java \
   GeckoAppShell.java \
   GeckoConnectivityReceiver.java \
   GeckoEvent.java \
   GeckoSurfaceView.java \
   GeckoInputConnection.java \
   AlertNotification.java \

new file mode 100644
--- /dev/null
+++ b/embedding/android/locales/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# 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/.
+

new file mode 100644
--- /dev/null
+++ b/embedding/android/moz.build
@@ -0,0 +1,6 @@
+# vim: set filetype=python:
+# 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/.
+
+DIRS += ['locales']

new file mode 100644
--- /dev/null
+++ b/embedding/base/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# 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/.
+

--- a/embedding/browser/Makefile.in
+++ b/embedding/browser/Makefile.in
@@ -4,12 +4,9 @@
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 DEPTH		= @DEPTH@
 topsrcdir	= @top_srcdir@
 srcdir		= @srcdir@
 VPATH		= @srcdir@
 
 include $(DEPTH)/config/autoconf.mk
-
-DIRS = webBrowser build
-
 include $(topsrcdir)/config/rules.mk

new file mode 100644
--- /dev/null
+++ b/embedding/browser/build/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# 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/.
+

new file mode 100644
--- /dev/null
+++ b/embedding/browser/moz.build
@@ -0,0 +1,6 @@
+# vim: set filetype=python:
+# 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/.
+
+DIRS += ['webBrowser', 'build']

new file mode 100644
--- /dev/null
+++ b/embedding/browser/webBrowser/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# 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/.
+

--- a/embedding/components/Makefile.in
+++ b/embedding/components/Makefile.in
@@ -4,23 +4,9 @@
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 DEPTH		= @DEPTH@
 topsrcdir	= @top_srcdir@
 srcdir		= @srcdir@
 VPATH		= @srcdir@
 
 include $(DEPTH)/config/autoconf.mk
-
-# You'd think we could skip building ui if XUL is disabled,
-# but we need to export interface headers from those directories.
-
-DIRS = windowwatcher appstartup/src find webbrowserpersist commandhandler
-
-ifdef MOZ_XUL
-ifdef NS_PRINTING
-DIRS += printingui/src
-endif
-endif
-
-DIRS += build
-
 include $(topsrcdir)/config/rules.mk

new file mode 100644
--- /dev/null
+++ b/embedding/components/appstartup/src/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# 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/.
+

new file mode 100644
--- /dev/null
+++ b/embedding/components/build/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# 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/.
+

--- a/embedding/components/commandhandler/Makefile.in
+++ b/embedding/components/commandhandler/Makefile.in
@@ -6,11 +6,10 @@
 DEPTH		= @DEPTH@
 topsrcdir	= @top_srcdir@
 srcdir		= @srcdir@
 VPATH		= @srcdir@
 
 include $(DEPTH)/config/autoconf.mk
 
 MODULE	= commandhandler
-DIRS = public src
 
 include $(topsrcdir)/config/rules.mk

new file mode 100644
--- /dev/null
+++ b/embedding/components/commandhandler/moz.build
@@ -0,0 +1,6 @@
+# vim: set filetype=python:
+# 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/.
+
+DIRS += ['public', 'src']

new file mode 100644
--- /dev/null
+++ b/embedding/components/commandhandler/public/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# 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/.
+

new file mode 100644
--- /dev/null
+++ b/embedding/components/commandhandler/src/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# 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/.
+

--- a/embedding/components/find/Makefile.in
+++ b/embedding/components/find/Makefile.in
@@ -6,11 +6,10 @@
 DEPTH		= @DEPTH@
 topsrcdir	= @top_srcdir@
 srcdir		= @srcdir@
 VPATH		= @srcdir@
 
 include $(DEPTH)/config/autoconf.mk
 
 MODULE		= find
-DIRS = public src
 
 include $(topsrcdir)/config/rules.mk

new file mode 100644
--- /dev/null
+++ b/embedding/components/find/moz.build
@@ -0,0 +1,6 @@
+# vim: set filetype=python:
+# 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/.
+
+DIRS += ['public', 'src']

new file mode 100644
--- /dev/null
+++ b/embedding/components/find/public/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# 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/.
+

new file mode 100644
--- /dev/null
+++ b/embedding/components/find/src/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# 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/.
+

new file mode 100644
--- /dev/null
+++ b/embedding/components/moz.build
@@ -0,0 +1,19 @@
+# vim: set filetype=python:
+# 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/.
+
+# You'd think we could skip building ui if XUL is disabled,
+# but we need to export interface headers from those directories.
+DIRS += [
+    'windowwatcher',
+    'appstartup/src',
+    'find',
+    'webbrowserpersist',
+    'commandhandler',
+]
+
+if CONFIG['MOZ_XUL'] and CONFIG['NS_PRINTING']:
+    DIRS += ['printingui/src']
+
+DIRS += ['build']

--- a/embedding/components/printingui/src/Makefile.in
+++ b/embedding/components/printingui/src/Makefile.in
@@ -4,28 +4,9 @@
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 DEPTH		= @DEPTH@
 topsrcdir	= @top_srcdir@
 srcdir		= @srcdir@
 VPATH		= @srcdir@
 
 include $(DEPTH)/config/autoconf.mk
-
-ifdef MOZ_PDF_PRINTING
-PLATFORM_DIR += unixshared
-endif
-
-ifeq ($(MOZ_WIDGET_TOOLKIT),os2)
-PLATFORM_DIR = os2
-endif
-
-ifeq ($(MOZ_WIDGET_TOOLKIT),windows)
-PLATFORM_DIR = win
-endif
-
-ifeq (cocoa,$(MOZ_WIDGET_TOOLKIT))
-PLATFORM_DIR = mac
-endif
-
-DIRS = $(PLATFORM_DIR)
-
 include $(topsrcdir)/config/rules.mk

new file mode 100644
--- /dev/null
+++ b/embedding/components/printingui/src/mac/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# 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/.
+

new file mode 100644
--- /dev/null
+++ b/embedding/components/printingui/src/moz.build
@@ -0,0 +1,15 @@
+# vim: set filetype=python:
+# 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/.
+
+toolkit = CONFIG['MOZ_WIDGET_TOOLKIT']
+
+if toolkit == 'os2':
+    DIRS += ['os2']
+elif toolkit == 'windows':
+    DIRS += ['win']
+elif toolkit == 'cocoa':
+    DIRS += ['mac']
+elif CONFIG['MOZ_PDF_PRINTING']:
+    DIRS += ['unixshared']

new file mode 100644
--- /dev/null
+++ b/embedding/components/printingui/src/os2/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# 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/.
+

new file mode 100644
--- /dev/null
+++ b/embedding/components/printingui/src/unixshared/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# 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/.
+

new file mode 100644
--- /dev/null
+++ b/embedding/components/printingui/src/win/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# 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/.
+

--- a/embedding/components/webbrowserpersist/Makefile.in
+++ b/embedding/components/webbrowserpersist/Makefile.in
@@ -6,11 +6,10 @@
 DEPTH		= @DEPTH@
 topsrcdir	= @top_srcdir@
 srcdir		= @srcdir@
 VPATH		= @srcdir@
 
 include $(DEPTH)/config/autoconf.mk
 
 MODULE	= webbrowserpersist
-DIRS = public src
 
 include $(topsrcdir)/config/rules.mk

new file mode 100644
--- /dev/null
+++ b/embedding/components/webbrowserpersist/moz.build
@@ -0,0 +1,6 @@
+# vim: set filetype=python:
+# 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/.
+
+DIRS += ['public', 'src']

new file mode 100644
--- /dev/null
+++ b/embedding/components/webbrowserpersist/public/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# 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/.
+

new file mode 100644
--- /dev/null
+++ b/embedding/components/webbrowserpersist/src/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# 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/.
+

--- a/embedding/components/windowwatcher/Makefile.in
+++ b/embedding/components/windowwatcher/Makefile.in
@@ -4,12 +4,9 @@
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 DEPTH		= @DEPTH@
 topsrcdir	= @top_srcdir@
 srcdir		= @srcdir@
 VPATH		= @srcdir@
 
 include $(DEPTH)/config/autoconf.mk
-
-DIRS = public src
-
 include $(topsrcdir)/config/rules.mk

new file mode 100644
--- /dev/null
+++ b/embedding/components/windowwatcher/moz.build
@@ -0,0 +1,6 @@
+# vim: set filetype=python:
+# 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/.
+
+DIRS += ['public', 'src']

new file mode 100644
--- /dev/null
+++ b/embedding/components/windowwatcher/public/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# 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/.
+

new file mode 100644
--- /dev/null
+++ b/embedding/components/windowwatcher/src/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# 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/.
+

new file mode 100644
--- /dev/null
+++ b/embedding/moz.build
@@ -0,0 +1,10 @@
+# vim: set filetype=python:
+# 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/.
+
+DIRS += ['base', 'components', 'browser']
+TEST_DIRS += ['test']
+
+if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'android' and CONFIG['MOZ_BUILD_APP'] in 'mobile/xul':
+    DIRS += ['android']

new file mode 100644
--- /dev/null
+++ b/embedding/test/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# 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/.
+

new file mode 100644
--- /dev/null
+++ b/embedding/tests/winEmbed/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# 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/.
+