Have DM manually encode its .png outputs.

gyp/libpng.gyp

Index: gyp/libpng.gyp
diff --git a/gyp/libpng.gyp b/gyp/libpng.gyp
index d918f2d403db2c795fd1d74980d9f819b5190039..45be5f7180ded5c363694af89d928c0ebb66d186 100644
--- a/gyp/libpng.gyp
+++ b/gyp/libpng.gyp
@@ -12,23 +12,26 @@
       'target_name': 'libpng',
       'type': 'none',
       'conditions': [
-        [ 'skia_os == "android"',
-          {
-            'dependencies': [
-              'android_deps.gyp:png',
-            ],
-            'export_dependent_settings': [
-              'android_deps.gyp:png',
-            ],
-          }, {  # skia_os != "android"
-            'dependencies': [
-              'libpng.gyp:libpng_static',
-            ],
-            'export_dependent_settings': [
-              'libpng.gyp:libpng_static',
-            ],
-          }
-        ]
+        [ 'skia_os == "android"', {
+            'dependencies':              [ 'android_deps.gyp:png' ],
+            'export_dependent_settings': [ 'android_deps.gyp:png' ],
+        },{
+            'dependencies':              [ 'libpng.gyp:libpng_static' ],
+            'export_dependent_settings': [ 'libpng.gyp:libpng_static' ],
+        }]
+      ]
+    },
+    {
+      'target_name': 'libpng_static_when_possible',
+      'type': 'none',
+      'conditions': [
+        [ 'skia_android_framework', {
+            'dependencies':              [ 'android_deps.gyp:png' ],
+            'export_dependent_settings': [ 'android_deps.gyp:png' ],
+        },{
+            'dependencies':              [ 'libpng.gyp:libpng_static' ],
+            'export_dependent_settings': [ 'libpng.gyp:libpng_static' ],
+        }]
       ]
     },
     {
@@ -83,7 +86,7 @@
           'defines': [
             'PNG_ARM_NEON_OPT=0',
           ],
-        }, { # skia_os != "ios" 
+        }, { # skia_os != "ios"
           'dependencies': [
             'libpng.gyp:libpng_static_neon',
           ],