add missing gl file for skia

skia/skia.gyp

 # Copyright (c) 2011 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 {
   'targets': [
     {
       'target_name': 'skia',
       'type': '<(library)',
       'msvs_guid': 'CD9CA56E-4E94-444C-87D4-58CA1E6F300D',
       'sources': [
         '../third_party/skia/gpu/src/GrAllocPool.cpp',
         '../third_party/skia/gpu/src/GrAtlas.cpp',
         '../third_party/skia/gpu/src/GrBufferAllocPool.cpp',
         '../third_party/skia/gpu/src/GrBufferAllocPool.h',
         '../third_party/skia/gpu/src/GrClip.cpp',
         '../third_party/skia/gpu/src/GrContext.cpp',
         '../third_party/skia/gpu/src/GrDrawTarget.cpp',
         '../third_party/skia/gpu/src/GrGLIndexBuffer.cpp',
+        '../third_party/skia/gpu/src/GrGLInterface.cpp',
         '../third_party/skia/gpu/src/GrGLTexture.cpp',
         '../third_party/skia/gpu/src/GrGLUtil.cpp',
         '../third_party/skia/gpu/src/GrGLVertexBuffer.cpp',
         '../third_party/skia/gpu/src/GrGpu.cpp',
         '../third_party/skia/gpu/src/GrGpuFactory.cpp',
         '../third_party/skia/gpu/src/GrGpuGL.cpp',
         '../third_party/skia/gpu/src/GrGpuGL.h',
         '../third_party/skia/gpu/src/GrGpuGLShaders2.cpp',
         '../third_party/skia/gpu/src/GrGpuGLShaders2.h',
         '../third_party/skia/gpu/src/GrInOrderDrawBuffer.cpp',
@@ skipping 844 matching lines @@
       ],
     },
   ],
 }
 
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 # tab-width:2
 # indent-tabs-mode:nil
 # End:
 # vim: set expandtab tabstop=2 shiftwidth=2: