[gimp] Only build Quartz-specific color picking code on OS X/Quartz builds

[Kristian Rietveld <kristian src gnome org>]

commit 153b19ac56e236bfcb4470351b968f1314718dfb
Author: Kristian Rietveld <kris loopnest org>
Date:   Sun Oct 4 18:11:16 2015 +0200

    Only build Quartz-specific color picking code on OS X/Quartz builds

 configure.ac               |    1 +
 libgimpwidgets/Makefile.am |    2 +-
 2 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index cbb3654..61dce6e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1946,6 +1946,7 @@ if test "x$platform_osx" != xno &&
   fi
 fi
 
+AM_CONDITIONAL(PLATFORM_OSX_QUARTZ, test "x$gtk_mac_integration_ok" = xyes)
 
 ####################################
 # Check for Mac OS X TWAIN framework
diff --git a/libgimpwidgets/Makefile.am b/libgimpwidgets/Makefile.am
index b88eed8..39f6770 100644
--- a/libgimpwidgets/Makefile.am
+++ b/libgimpwidgets/Makefile.am
@@ -286,7 +286,7 @@ EXTRA_DIST = \
 #
 
 
-if PLATFORM_OSX
+if PLATFORM_OSX_QUARTZ
 libgimpwidgets_sources += gimppickbutton-quartz.c
 AM_CPPFLAGS += "-xobjective-c"
 else