prepare skia for shared library build on android

gyp/core.gyp

Index: gyp/core.gyp
diff --git a/gyp/core.gyp b/gyp/core.gyp
index 9e0792b7734be1dfced1715b21bf3fe93838eef6..d018cbea234d35a88cc615cebbf28f64b592ff91 100644
--- a/gyp/core.gyp
+++ b/gyp/core.gyp
@@ -76,6 +76,11 @@
             'config/win',
           ],
         }],
+        [ 'skia_os == "android"', {
+          'sources': [
+            '../src/core/SkPaintOptionsAndroid.cpp',
+          ],
+        }],
         [ 'skia_os == "android" and skia_arch_type == "arm" and armv7 == 1', {
           # The code in SkUtilsArm.cpp can be used on an ARM-based Linux system, not only Android.
           'sources': [
@@ -120,9 +125,6 @@
           }],
         ],
       },
-      'dependencies': [
-        'opts.gyp:opts'
-      ],
     },
   ],
 }