Improve Ganesh helpers.

mojo/skia/BUILD.gn

 # Copyright 2014 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.
 
 source_set("skia") {
   sources = [
     "ganesh_context.cc",
     "ganesh_context.h",
     "ganesh_framebuffer_surface.cc",
     "ganesh_framebuffer_surface.h",
+    "ganesh_helpers.cc",
+    "ganesh_helpers.h",
     "ganesh_texture_surface.cc",
     "ganesh_texture_surface.h",
   ]
 
   deps = [
     ":skia_bindings",
     "//base",
     "//mojo/gpu",
     "//mojo/public/c/gpu",
     "//mojo/public/c/gpu:MGL",
     "//skia",
   ]
 }
 
 source_set("skia_bindings") {
   sources = [
     "gl_bindings_skia.cc",
     "gl_bindings_skia.h",
   ]
   deps = [
     "//mojo/public/c/gpu",
     "//mojo/public/c/gpu:GLES2",
     "//skia",
   ]
 }