Treat bad values passed to --images as a fatal error

gyp/codec.gyp

Index: gyp/codec.gyp
diff --git a/gyp/codec.gyp b/gyp/codec.gyp
index eb87de1faa04e4bfd660cdd26de7a091830e60c2..0f49ee4c441a6a61675bd57d3e1d0ca3e9e742b4 100644
--- a/gyp/codec.gyp
+++ b/gyp/codec.gyp
@@ -67,8 +67,7 @@
         'TURBO_HAS_SKIP',
       ],
       'conditions': [
-        # FIXME: fix the support for ChromeOS [DNG SDK issue with clock_gettime()].
-        ['skia_codec_decodes_raw and skia_os != "chromeos"', {
+        ['skia_codec_decodes_raw', {

[scroggo, 2016/01/27 19:42:27]

Now this flag is only true on platforms where it's supported, rather than being
part of the picture.

           'dependencies': [
             'raw_codec',
           ],
@@ -76,7 +75,7 @@
       ],
     }, {
       # RAW codec needs exceptions. Due to that, it is a separate target. Its usage can be
-      # controlled by SK_CODEC_DECODES_RAW flag.
+      # controlled by skia_codec_decodes_raw flag.
       'target_name': 'raw_codec',
       'product_name': 'raw_codec',
       'type': 'static_library',
@@ -110,13 +109,7 @@
         'include_dirs': [
           '../include/codec',
         ],
-        'defines': [
-          'SK_CODEC_DECODES_RAW',

[scroggo, 2016/01/27 19:42:27]

This is now defined everywhere, so it can be shared by flags.

-        ],
       },
-      'defines': [
-        'SK_CODEC_DECODES_RAW',
-      ],
       'conditions': [
         ['skia_arch_type == "x86" or skia_arch_type == "arm"', {
           'defines': [