Move GrDrawTarget::clear logic into GrDrawContext

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 210 matching lines @@
       '<(skia_src_path)/gpu/batches/GrAAConvexPathRenderer.h',
       '<(skia_src_path)/gpu/batches/GrAAFillRectBatch.cpp',
       '<(skia_src_path)/gpu/batches/GrAAFillRectBatch.h',
       '<(skia_src_path)/gpu/batches/GrAAStrokeRectBatch.cpp',
       '<(skia_src_path)/gpu/batches/GrAAStrokeRectBatch.h',
       '<(skia_src_path)/gpu/batches/GrAtlasTextBatch.cpp',
       '<(skia_src_path)/gpu/batches/GrAtlasTextBatch.h',
       '<(skia_src_path)/gpu/batches/GrBatch.cpp',
       '<(skia_src_path)/gpu/batches/GrBatch.h',
       '<(skia_src_path)/gpu/batches/GrClearBatch.h',
+      '<(skia_src_path)/gpu/batches/GrClearStencilClipBatch.h',
       '<(skia_src_path)/gpu/batches/GrCopySurfaceBatch.cpp',
       '<(skia_src_path)/gpu/batches/GrCopySurfaceBatch.h',
       '<(skia_src_path)/gpu/batches/GrDashLinePathRenderer.cpp',
       '<(skia_src_path)/gpu/batches/GrDashLinePathRenderer.h',
       '<(skia_src_path)/gpu/batches/GrDefaultPathRenderer.cpp',
       '<(skia_src_path)/gpu/batches/GrDefaultPathRenderer.h',
       '<(skia_src_path)/gpu/batches/GrDiscardBatch.h',
       '<(skia_src_path)/gpu/batches/GrDrawBatch.cpp',
       '<(skia_src_path)/gpu/batches/GrDrawBatch.h',
       '<(skia_src_path)/gpu/batches/GrDrawAtlasBatch.cpp',
@@ skipping 284 matching lines @@
       '<(skia_src_path)/gpu/gl/win/GrGLCreateNativeInterface_win.cpp',
       '<(skia_src_path)/gpu/gl/glx/GrGLCreateNativeInterface_glx.cpp',
       '<(skia_src_path)/gpu/gl/egl/GrGLCreateNativeInterface_egl.cpp',
       '<(skia_src_path)/gpu/gl/iOS/GrGLCreateNativeInterface_iOS.cpp',
       '<(skia_src_path)/gpu/gl/android/GrGLCreateNativeInterface_android.cpp',
     ],
     'skgpu_null_gl_sources': [
     ],
   },
 }