Add and use SkSemaphore

gyp/core.gypi

 # Copyright 2015 Google Inc.
 #
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 # Include this gypi to include all 'core' files
 # The parent gyp/gypi file must define
 #       'skia_src_path'     e.g. skia/trunk/src
 #       'skia_include_path' e.g. skia/trunk/include
 #
 # The skia build defines these in common_variables.gypi
@@ skipping 174 matching lines @@
         '<(skia_src_path)/core/SkScalar.cpp',
         '<(skia_src_path)/core/SkScalerContext.cpp',
         '<(skia_src_path)/core/SkScalerContext.h',
         '<(skia_src_path)/core/SkScan.cpp',
         '<(skia_src_path)/core/SkScan.h',
         '<(skia_src_path)/core/SkScanPriv.h',
         '<(skia_src_path)/core/SkScan_AntiPath.cpp',
         '<(skia_src_path)/core/SkScan_Antihair.cpp',
         '<(skia_src_path)/core/SkScan_Hairline.cpp',
         '<(skia_src_path)/core/SkScan_Path.cpp',
+        '<(skia_src_path)/core/SkSemaphore.cpp',
         '<(skia_src_path)/core/SkShader.cpp',
         '<(skia_src_path)/core/SkSpriteBlitter_ARGB32.cpp',
         '<(skia_src_path)/core/SkSpriteBlitter_RGB16.cpp',
         '<(skia_src_path)/core/SkSpriteBlitter.h',
         '<(skia_src_path)/core/SkSpriteBlitterTemplate.h',
         '<(skia_src_path)/core/SkStream.cpp',
         '<(skia_src_path)/core/SkStreamPriv.h',
         '<(skia_src_path)/core/SkString.cpp',
         '<(skia_src_path)/core/SkStringUtils.cpp',
         '<(skia_src_path)/core/SkStroke.h',
@@ skipping 188 matching lines @@
         '<(skia_src_path)/pathops/SkPathOpsLine.h',
         '<(skia_src_path)/pathops/SkPathOpsPoint.h',
         '<(skia_src_path)/pathops/SkPathOpsQuad.h',
         '<(skia_src_path)/pathops/SkPathOpsRect.h',
         '<(skia_src_path)/pathops/SkPathOpsTSect.h',
         '<(skia_src_path)/pathops/SkPathOpsTypes.h',
         '<(skia_src_path)/pathops/SkPathWriter.h',
         '<(skia_src_path)/pathops/SkReduceOrder.h',
     ],
 }