gif2webp: Move GIF decoding related code to a support library.

Change-Id: Ifa5e663eb0db7e1e08174fe6608bd45950281abb

Makefile.vc

@@ -232,6 +232,9 @@ EX_FORMAT_DEC_OBJS = \
     $(DIROBJ)\examples\webpdec.obj \
     $(DIROBJ)\examples\wicdec.obj \
 
+EX_GIF_DEC_OBJS = \
+    $(DIROBJ)\examples\gifdec.obj \
+
 EX_UTIL_OBJS = \
     $(DIROBJ)\examples\example_util.obj \
 
@@ -302,8 +305,8 @@ gif2webp: $(DIRBIN)\gif2webp.exe
 
 $(DIRBIN)\cwebp.exe: $(DIROBJ)\examples\cwebp.obj $(EX_FORMAT_DEC_OBJS)
 $(DIRBIN)\dwebp.exe: $(DIROBJ)\examples\dwebp.obj
-$(DIRBIN)\gif2webp.exe: $(DIROBJ)\examples\gif2webp.obj $(EX_UTIL_OBJS)
-$(DIRBIN)\gif2webp.exe: $(LIBWEBPMUX) $(LIBWEBP)
+$(DIRBIN)\gif2webp.exe: $(DIROBJ)\examples\gif2webp.obj $(EX_GIF_DEC_OBJS)
+$(DIRBIN)\gif2webp.exe: $(EX_UTIL_OBJS) $(LIBWEBPMUX) $(LIBWEBP)
 $(DIRBIN)\vwebp.exe: $(DIROBJ)\examples\vwebp.obj
 $(DIRBIN)\vwebp.exe: $(EX_UTIL_OBJS) $(LIBWEBPDEMUX) $(LIBWEBP)
 $(DIRBIN)\webpmux.exe: $(DIROBJ)\examples\webpmux.obj $(LIBWEBPMUX)

examples/Makefile.am

@@ -32,7 +32,7 @@ cwebp_CPPFLAGS += $(JPEG_INCLUDES) $(PNG_INCLUDES) $(TIFF_INCLUDES)
 cwebp_LDADD  = libexampleutil.la ../src/libwebp.la
 cwebp_LDADD += $(JPEG_LIBS) $(PNG_LIBS) $(TIFF_LIBS)
 
-gif2webp_SOURCES = gif2webp.c
+gif2webp_SOURCES = gif2webp.c gifdec.c gifdec.h
 gif2webp_CPPFLAGS = $(AM_CPPFLAGS) $(USE_EXPERIMENTAL_CODE) $(GIF_INCLUDES)
 gif2webp_LDADD  = libexampleutil.la ../src/mux/libwebpmux.la ../src/libwebp.la
 gif2webp_LDADD += $(GIF_LIBS)