spin off easy stuff from Herb's windows GN CL

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.
 
 declare_args() {
 }
 
 skia_public_includes = [
   "include/android",
@@ skipping 35 matching lines @@
     "src/gpu",
     "src/image",
     "src/images",
     "src/lazy",
     "src/opts",
     "src/pathops",
     "src/pdf",
     "src/ports",
     "src/sfnt",
     "src/utils",
+    "src/utils/win",
     "third_party/etc1",
     "third_party/ktx",
   ]
 
   defines = [
     "SK_GAMMA_APPLY_TO_A8",
 
     "SK_HAS_GIF_LIBRARY",
     "SK_HAS_JPEG_LIBRARY",
     "SK_HAS_PNG_LIBRARY",
@@ skipping 101 matching lines @@
     ":opts_sse41",
     ":opts_ssse3",
     "//third_party/expat",
     "//third_party/giflib",
     "//third_party/libjpeg_turbo",
     "//third_party/libpng",
     "//third_party/libwebp",
     "//third_party/zlib",
   ]
 
-  libs = [ "pthread" ]
+  if (!is_win) {
+    libs = [ "pthread" ]
+  }
 
   sources = []
   sources += core_gypi.sources
   sources += effects_gypi.sources
   sources += gpu_gypi.skgpu_sources
   sources += opts_gypi.sse2_sources
   sources += pdf_gypi.sources
   sources += utils_gypi.sources
   sources += [
     "src/android/SkBitmapRegionCodec.cpp",
@@ skipping 50 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" ]
   } else {
     sources += [
       "src/ports/SkDebug_stdio.cpp",
       "src/ports/SkOSFile_posix.cpp",
       "src/ports/SkTLS_pthread.cpp",
       "src/xps/SkDocument_XPS_None.cpp",
     ]
   }
 
   if (is_linux) {
@@ skipping 280 matching lines @@
       ":flags",
       ":gm",
       ":gpu_tool_utils",
       ":skia",
       ":tool_utils",
       "//third_party/jsoncpp",
     ]
     testonly = true
   }
 }