Create stub GrAuditTrail class

gyp/gpu.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 'gpu' 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 37 matching lines @@
       '<(skia_include_path)/gpu/effects/GrXfermodeFragmentProcessor.h',
 
       '<(skia_include_path)/gpu/gl/GrGLConfig.h',
       '<(skia_include_path)/gpu/gl/GrGLExtensions.h',
       '<(skia_include_path)/gpu/gl/GrGLFunctions.h',
       '<(skia_include_path)/gpu/gl/GrGLInterface.h',
       '<(skia_include_path)/gpu/gl/GrGLSLPrettyPrint.h',
       '<(skia_include_path)/gpu/gl/GrGLTypes.h',
 
       # Private includes
+      '<(skia_include_path)/private/GrAuditTrail.h',
       '<(skia_include_path)/private/GrSingleOwner.h',
 
+      '<(skia_src_path)/gpu/GrAuditTrail.cpp',
       '<(skia_src_path)/gpu/GrAutoLocaleSetter.h',
       '<(skia_src_path)/gpu/GrAllocator.h',
       '<(skia_src_path)/gpu/GrBatchAtlas.cpp',
       '<(skia_src_path)/gpu/GrBatchAtlas.h',
       '<(skia_src_path)/gpu/GrBatchFlushState.cpp',
       '<(skia_src_path)/gpu/GrBatchFlushState.h',
       '<(skia_src_path)/gpu/GrBatchTest.cpp',
       '<(skia_src_path)/gpu/GrBatchTest.h',
       '<(skia_src_path)/gpu/GrBlend.cpp',
       '<(skia_src_path)/gpu/GrBlurUtils.cpp',
@@ skipping 413 matching lines @@
       '<(skia_src_path)/gpu/gl/debug/SkDebugGLContext.cpp',
       '<(skia_src_path)/gpu/gl/debug/SkDebugGLContext.h',
     ],
     'skgpu_null_gl_sources': [
       '<(skia_src_path)/gpu/gl/GrGLCreateNullInterface.cpp',
       '<(skia_src_path)/gpu/gl/SkNullGLContext.cpp',
       '<(skia_include_path)/gpu/gl/SkNullGLContext.h',
     ],
   },
 }