add stroke params to c api

BUG=skia:
TBR=

Review URL: https://codereview.chromium.org/848553002
diff --git a/gyp/core.gypi b/gyp/core.gypi
index 7d05cbd..c5cecb6 100644
--- a/gyp/core.gypi
+++ b/gyp/core.gypi
@@ -7,8 +7,9 @@
 #
 {
     'sources': [
+        '<(skia_src_path)/c/sk_paint.cpp',
         '<(skia_src_path)/c/sk_surface.cpp',
-        '<(skia_include_path)/c/sk_surface.h',
+        '<(skia_src_path)/c/sk_types_priv.h',
 
         '<(skia_src_path)/core/SkAAClip.cpp',
         '<(skia_src_path)/core/SkAnnotation.cpp',