add shell for libwebpextras

meant to contain additional utility functions useful in processing webp
input/output.

Change-Id: I014ae6b917d62e826aa23a3bbe99aac4462a97c2

configure.ac

@@ -28,6 +28,7 @@ AC_ARG_ENABLE([everything],
                               disabled with --disable-target]),
               [SET_IF_UNSET([enable_libwebpdecoder], [$enableval])
                SET_IF_UNSET([enable_libwebpdemux], [$enableval])
+               SET_IF_UNSET([enable_libwebpextras], [$enableval])
                SET_IF_UNSET([enable_libwebpmux], [$enableval])])
 
 AC_ARG_WITH([pkgconfigdir], AS_HELP_STRING([--with-pkgconfigdir=DIR],
@@ -527,6 +528,14 @@ AC_ARG_ENABLE([libwebpdecoder],
 AC_MSG_RESULT(${enable_libwebpdecoder-no})
 AM_CONDITIONAL([BUILD_LIBWEBPDECODER], [test "$enable_libwebpdecoder" = "yes"])
 
+dnl === Check whether libwebpextras should be built
+AC_MSG_CHECKING(whether libwebpextras is to be built)
+AC_ARG_ENABLE([libwebpextras],
+              AS_HELP_STRING([--enable-libwebpextras],
+                             [Build libwebpextras @<:@default=no@:>@]))
+AC_MSG_RESULT(${enable_libwebpextras-no})
+AM_CONDITIONAL([WANT_EXTRAS], [test "$enable_libwebpextras" = "yes"])
+
 dnl =========================
 
 AC_CONFIG_MACRO_DIR([m4])
@@ -535,9 +544,10 @@ AC_CONFIG_FILES([Makefile src/Makefile man/Makefile \
                  examples/Makefile src/dec/Makefile \
                  src/enc/Makefile src/dsp/Makefile \
                  src/demux/Makefile src/mux/Makefile \
-                 src/utils/Makefile \
+                 src/utils/Makefile src/extras/Makefile \
                  src/libwebp.pc src/libwebpdecoder.pc \
-                 src/demux/libwebpdemux.pc src/mux/libwebpmux.pc])
+                 src/demux/libwebpdemux.pc src/mux/libwebpmux.pc \
+                 src/extras/libwebpextras.pc])
 
 
 AC_OUTPUT
@@ -553,6 +563,7 @@ libwebp: yes
 libwebpdecoder: ${enable_libwebpdecoder-no}
 libwebpdemux: ${enable_libwebpdemux-no}
 libwebpmux: ${enable_libwebpmux-no}
+libwebpextras: ${enable_libwebpextras-no}
 
 Tools:
 cwebp : yes