Initial KTX file decoder

gyp/images.gyp

 # GYP file for images project.
 {
   'targets': [
     {
       'target_name': 'images',
       'product_name': 'skia_images',
       'type': 'static_library',
       'standalone_static_library': 1,
       'dependencies': [
         'core.gyp:*',
         'libjpeg.gyp:*',
         'etc1.gyp:libetc1',
+        'ktx.gyp:libSkKTX',
         'libwebp.gyp:libwebp',
         'utils.gyp:utils',
       ],
       'conditions': [
         [ 'skia_android_framework == 0', {
           'export_dependent_settings': [
             'libjpeg.gyp:*',
           ],
         }],
       ],
@@ skipping 31 matching lines @@
 
         # IMPORTANT: The build order of the SkImageDecoder_*.cpp files
         # defines the order image decoders are tested when decoding a
         # stream. The last decoder is the first one tested, so the .cpp
         # files should be in listed in order from the least likely to be
         # used, to the most likely (jpeg and png should be the last two
         # for instance.) As a result, they are deliberately not in
         # alphabetical order.
         '../src/images/SkImageDecoder_wbmp.cpp',
         '../src/images/SkImageDecoder_pkm.cpp',
+        '../src/images/SkImageDecoder_ktx.cpp',
         '../src/images/SkImageDecoder_libbmp.cpp',
         '../src/images/SkImageDecoder_libgif.cpp',
         '../src/images/SkImageDecoder_libico.cpp',
         '../src/images/SkImageDecoder_libwebp.cpp',
         '../src/images/SkImageDecoder_libjpeg.cpp',
         '../src/images/SkImageDecoder_libpng.cpp',
 
         '../src/images/SkImageEncoder.cpp',
         '../src/images/SkImageEncoder_Factory.cpp',
         '../src/images/SkImageEncoder_argb.cpp',
@@ skipping 100 matching lines @@
         }],
       ],
       'direct_dependent_settings': {
         'include_dirs': [
           '../include/images',
         ],
       },
     },
   ],
 }