Enable shared library build

gyp/images.gyp

Index: gyp/images.gyp
===================================================================
--- gyp/images.gyp	(revision 9315)
+++ gyp/images.gyp	(working copy)
@@ -9,7 +9,6 @@
       'dependencies': [
         'libjpeg.gyp:*',
         'libwebp.gyp:libwebp',
-        'utils.gyp:utils',
       ],
       'export_dependent_settings': [
         'libjpeg.gyp:*',
@@ -96,6 +95,9 @@
             '../src/images/SkImageDecoder_libgif.cpp',
             '../src/images/SkMovie_gif.cpp',
           ],
+          'include_dirs': [
+            '../include/utils/mac',
+          ],
         },{ #else if skia_os != mac
           'sources!': [
             '../src/ports/SkImageDecoder_CG.cpp',
@@ -106,9 +108,6 @@
           # our code that calls it.
           # See http://code.google.com/p/gyp/wiki/InputFormatReference#Dependent_Settings
           'link_settings': {
-            'sources': [
-              '../src/images/SkImageDecoder_libpng.cpp',
-            ],
             'libraries': [
               '-lgif',
               '-lpng',
@@ -126,9 +125,6 @@
             '../src/images/SkMovie_gif.cpp',
           ],
           'link_settings': {
-            'sources': [
-              '../src/images/SkImageDecoder_libpng.cpp',
-            ],
             'libraries': [
               '-lpng',
               '-lz',
@@ -149,11 +145,6 @@
             '../src/images/SkImageRef_ashmem.cpp',
           ],
         }],
-        [ 'skia_os == "ios"', {
-           'include_dirs': [
-             '../include/utils/mac',
-           ],
-        }],
       ],
       'direct_dependent_settings': {
         'include_dirs': [