Compile the skia library for windows using gn.

BUILD.gn

 # Copyright 2016 Google Inc.
 #
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("gn/shared_sources.gni")
 
 declare_args() {
   skia_enable_tools = !is_fuchsia && !is_component_build
 
@@ skipping 386 matching lines @@
     ":sse2",
     ":sse41",
     ":sse42",
     ":ssse3",
     ":typeface_freetype",
     ":vulkan",
     ":webp",
     ":xml",
   ]
 
+  if (!is_win) {

[mtklein, 2016/09/14 21:25:14]

Probably redundant.

[herb_g, 2016/09/16 19:54:15]

Done.

+    libs = [ "pthread" ]
+  }
+  
   sources = []
   sources += skia_core_sources
   sources += skia_effects_sources
   sources += skia_gpu_sources
   sources += skia_sksl_sources
   sources += skia_utils_sources
   sources += [
     "src/android/SkBitmapRegionCodec.cpp",
     "src/android/SkBitmapRegionDecoder.cpp",
     "src/codec/SkAndroidCodec.cpp",
@@ skipping 45 matching lines @@
       "src/ports/SkFontMgr_win_dw.cpp",
       "src/ports/SkFontMgr_win_dw_factory.cpp",
       "src/ports/SkImageEncoder_WIC.cpp",
       "src/ports/SkImageGeneratorWIC.cpp",
       "src/ports/SkOSFile_win.cpp",
       "src/ports/SkScalerContext_win_dw.cpp",
       "src/ports/SkTLS_win.cpp",
       "src/ports/SkTypeface_win_dw.cpp",
       "src/xps/SkDocument_XPS.cpp",
     ]
-    sources -= [ "src/utils/SkThreadUtils_pthread.cpp" ]
+    sources -= [ get_path_info("src/utils/SkThreadUtils_pthread.cpp", "abspath") ]
   } else {
     sources += [
       "src/ports/SkOSFile_posix.cpp",
       "src/ports/SkTLS_pthread.cpp",
       "src/xps/SkDocument_XPS_None.cpp",
     ]
   }
 
   if (is_android) {
     deps += [
@@ skipping 348 matching lines @@
     sources = [
       "tools/SkShaper_primitive.cpp",
       "tools/using_skia_and_harfbuzz.cpp",
     ]
     deps = [
       ":skia",
     ]
     testonly = true
   }
 }