Build & link libpng as static library everywhere*

gyp/common_variables.gypi

Index: gyp/common_variables.gypi
diff --git a/gyp/common_variables.gypi b/gyp/common_variables.gypi
index dd2c084ff54bb179f17e43ad8c71299ecbea536d..d089512cd3f26b74056a3b39827fdbd39ccace59 100644
--- a/gyp/common_variables.gypi
+++ b/gyp/common_variables.gypi
@@ -76,10 +76,16 @@
           'skia_os%': 'android',
           'skia_chrome_utils%': 0,
           'skia_use_system_json%': 1,
+          # skia_libpng_static - instead of linking libpng with '-lpng' and
+          #     including the headers from '/usr/include/png.h', compile and
+          #     statically link the version of libpng in
+          #     third_party/externals/libpng.
+          'skia_libpng_static%': '0',
         }, {
           'skia_os%': '<(skia_os)',
           'skia_chrome_utils%': 1,
           'skia_use_system_json%': 0,
+          'skia_libpng_static%': '1',
         }],
         [ 'skia_os == "win"', {
           'os_posix%': 0,
@@ -121,16 +127,6 @@
             'skia_freetype_static%': '0',
           }
         ],
-        [ 'skia_os in ["mac", "ios", "win"]', {
-            # skia_libpng_static - instead of linking libpng with '-lpng' and
-            #     including the headers from '/usr/include/png.h', compile and
-            #     statically link the version of libpng in
-            #     third_party/externals/libpng.
-            'skia_libpng_static%': '1',
-          }, {
-            'skia_libpng_static%': '0',
-          }
-        ],
       ],
 
       # skia_giflib_static - on OS variants that normally would link giflib