Individually enable and disable SkCodecs

public.bzl

 ################################################################################
 # Skylark macros
 ################################################################################
 
 is_bazel = not hasattr(native, "genmpm")
 
 def portable_select(select_dict, bazel_condition, default_condition):
   """Replaces select() with a Bazel-friendly wrapper.
 
   Args:
@@ skipping 466 matching lines @@
 DEFINES_UNIX = [
     "PNG_SKIP_SETJMP_CHECK",
     "SK_BUILD_FOR_UNIX",
     "SK_SAMPLES_FOR_X",
     "SK_SFNTLY_SUBSETTER",
     "SK_CODEC_DECODES_RAW",
 ]
 
 DEFINES_ANDROID = [
     "SK_BUILD_FOR_ANDROID",
-    # TODO(benjaminwagner): Try to get png library updated?

[msarett, 2016/02/16 22:24:22]

INDEX_SUPPORTED is not a feature of a newer libpng.  It is a feature of
Android's forked libpng (which we have recently removed :)).  We intentionally
don't support this anymore.

-    "SK_PNG_NO_INDEX_SUPPORTED",
     "SK_CODEC_DECODES_RAW",
 ]
 
 DEFINES_IOS = [
     "SK_BUILD_FOR_IOS",
     "SK_IGNORE_ETC1_SUPPORT",
     "SKNX_NO_SIMD",
 ]
 
 DEFINES_ALL = [
     # Chrome DEFINES.
     "SK_USE_FLOATBITS",
     "SK_USE_FREETYPE_EMBOLDEN",
     # Turn on a few Google3-specific build fixes.
     "GOOGLE3",
+    # Turn on image codecs

[dogben, 2016/02/16 22:31:16]

We have removed all dependencies for the iOS Google3 build. Could you add these
to DEFINES_UNIX and DEFINES_ANDROID instead?

[msarett, 2016/02/16 22:33:54]

Yes.  Though we should be able to keep BMP and WBMP here, since they have no
dependencies.

How does this work now?  Ex: It seems like JPEG is always enabled, yet there are
no libjpegs on iOS?

[msarett, 2016/02/17 14:34:53]

Thanks, removing these on iOS.

+    "SK_CODEC_DECODES_BMP",
+    "SK_CODEC_DECODES_GIF",
+    "SK_CODEC_DECODES_ICO",
+    "SK_CODEC_DECODES_JPEG",
+    "SK_CODEC_DECODES_PNG",
+    "SK_CODEC_DECODES_WBMP",
+    "SK_CODEC_DECODES_WEBP",
 ]
 
 ################################################################################
 ## LINKOPTS
 ################################################################################
 
 LINKOPTS_UNIX = []
 
 LINKOPTS_ANDROID = [
     "-lEGL",
 ]
 
 LINKOPTS_IOS = []
 
 LINKOPTS_ALL = [
     "-ldl",
 ]