Port SkBlitRow::Color32 to SkOpts.

src/opts/SkBlitRow_opts_none.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBlitRow.h"
 
 // Platform impl of Platform_procs with no overrides
 
 SkBlitRow::Proc16 SkBlitRow::PlatformFactory565(unsigned flags) {
     return nullptr;
 }
 
 SkBlitRow::ColorProc16 SkBlitRow::PlatformColorFactory565(unsigned flags) {
     return nullptr;
 }
 
 SkBlitRow::Proc32 SkBlitRow::PlatformProcs32(unsigned flags) {
     return nullptr;
 }
-
-SkBlitRow::Color32Proc SkBlitRow::PlatformColor32Proc() { return nullptr; }