Individually enable and disable SkCodecs

gyp/common_conditions.gypi

 # Copyright 2015 Google Inc.
 #
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # conditions used in both common.gypi and skia.gyp in chromium
 #
 {
   'defines': [
     'SK_ALLOW_STATIC_GLOBAL_INITIALIZERS=<(skia_static_initializers)',
     'SK_SUPPORT_GPU=<(skia_gpu)',
     'SK_FORCE_DISTANCE_FIELD_TEXT=<(skia_force_distance_field_text)',
+    
+    # Allow the client to turn on/off individual codecs.  This can be useful
+    # when some of the dependencies are not present.
+    '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',
   ],
   'conditions' : [
     [ 'skia_codec_decodes_raw', {
       'defines': [
         'SK_CODEC_DECODES_RAW',
       ],
     }],
     ['skia_pic', {
      'cflags': [
        '-fPIC',
@@ skipping 650 matching lines @@
           'LD_RUNPATH_SEARCH_PATHS': ['@executable_path/.'],
       },
     }],
 
   ], # end 'conditions'
   # The Xcode SYMROOT must be at the root. See build/common.gypi in chromium for more details
   'xcode_settings': {
     'SYMROOT': '<(DEPTH)/xcodebuild',
   },
 }