fix windows build; add blend modes

third_party/third_party.gyp

Index: third_party/third_party.gyp
diff --git a/third_party/third_party.gyp b/third_party/third_party.gyp
index 665de0a1465bd477c78c6f36ad6c8d4d5d1c0c7f..7fd108245447ca02a871a002baaef9a16ebc0e6c 100644
--- a/third_party/third_party.gyp
+++ b/third_party/third_party.gyp
@@ -5,6 +5,7 @@
 {
   'variables': {
     'pdf_enable_xfa%': 0,  # Set to 1 by standalone.gypi in standalone builds.
+    'pdf_use_skia%': 0,
   },
   'target_defaults': {
     'defines': [
@@ -80,6 +81,15 @@
         'freetype/src/truetype/truetype.c',
         'freetype/src/type1/type1.c',
       ],
+      'conditions': [
+        ['pdf_use_skia==1', {
+          'sources': [
+           'freetype/src/base/ftfntfmt.c',
+           'freetype/src/base/ftfstype.c',
+           'freetype/src/base/fttype1.c',
+          ],
+        }],
+      ],
       'variables': {
         'clang_warning_flags': [
           # open_face_PS_from_sfnt_stream() and open_face_from_buffer() in