GN Windows build fixes

skia/skia_gn_files.gypi

 # This file is read into the GN build.
 
 # Files are relative to third_party/skia.
 {
   # Shared defines for all builds.
   'skia_feature_defines': [
     'GR_GL_CUSTOM_SETUP_HEADER="GrGLConfig_chrome.h"',
     'GR_GL_IGNORE_ES3_MSAA=0',
     'SK_ATTR_DEPRECATED=SK_NOTHING_ARG1',
     'SK_DEFERRED_CANVAS_USES_FACTORIES=1',
@@ skipping 771 matching lines @@
     '<(skia_src_path)/ports/SkFontHost_linux.cpp',
     '<(skia_src_path)/ports/SkFontHost_mac.cpp',
     '<(skia_src_path)/ports/SkFontHost_win.cpp',
     '<(skia_src_path)/ports/SkFontHost_win_dw.cpp',
     '<(skia_src_path)/ports/SkFontMgr_default_gdi.cpp',
     '<(skia_src_path)/ports/SkGlobalInitialization_chromium.cpp',
     '<(skia_src_path)/ports/SkImageDecoder_empty.cpp',
     '<(skia_src_path)/ports/SkOSFile_posix.cpp',
     '<(skia_src_path)/ports/SkOSFile_stdio.cpp',
     '<(skia_src_path)/ports/SkOSFile_win.cpp',
-    '<(skia_src_path)/ports/SkThread_win.cpp',
     '<(skia_src_path)/ports/SkTime_Unix.cpp',
     '<(skia_src_path)/ports/SkTLS_pthread.cpp',
     '<(skia_src_path)/ports/SkTLS_win.cpp',
     '<(skia_src_path)/sfnt/SkOTTable_name.cpp',
     '<(skia_src_path)/sfnt/SkOTTable_name.h',
     '<(skia_src_path)/sfnt/SkOTUtils.cpp',
     '<(skia_src_path)/sfnt/SkOTUtils.h',
     '<(skia_src_path)/utils/debugger/SkDebugCanvas.cpp',
     '<(skia_src_path)/utils/debugger/SkDebugCanvas.h',
     '<(skia_src_path)/utils/debugger/SkDrawCommand.cpp',
@@ skipping 70 matching lines @@
     '<(skia_src_path)/utils/win/SkDWriteGeometrySink.h',
     '<(skia_src_path)/utils/win/SkHRESULT.cpp',
     '<(skia_src_path)/utils/win/SkIStream.cpp',
     '<(skia_src_path)/utils/win/SkWGL_win.cpp',
 
     #testing
     '<(skia_src_path)/fonts/SkGScalerContext.cpp',
     '<(skia_src_path)/fonts/SkGScalerContext.h',
   ],
 }