Replace SkTLazy with base::Optional

skia/ext/opacity_filter_canvas.cc

 // Copyright 2015 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.
 
 #include "skia/ext/opacity_filter_canvas.h"
 #include "third_party/skia/include/core/SkPaint.h"
-#include "third_party/skia/include/core/SkTLazy.h"
 
 namespace skia {
 
 OpacityFilterCanvas::OpacityFilterCanvas(SkCanvas* canvas,
                                          float opacity,
                                          bool disable_image_filtering)
     : INHERITED(canvas),
       alpha_(SkScalarRoundToInt(opacity * 255)),
       disable_image_filtering_(disable_image_filtering) { }
 
 bool OpacityFilterCanvas::onFilter(SkTCopyOnFirstWrite<SkPaint>* paint, Type) const {

[bungeman-chromium, 2016/04/27 18:32:54]

Unfortunately (and I hadn't looked at this before) SkTLazy.h also provides this
SkTCopyOnFirstWrite class. We need to get Chromium off of that as well in order
to hide SkTLazy.h.

[vmpstr, 2016/04/27 18:36:52]

I think that it's ok to include SkTLazy.h (especially in something like
skia/ext). We just want to avoid using SkTLazy type, since base::Optional is
preferred. 

[vmpstr, 2016/04/27 18:39:34]

That being said, opacity_filter_canvas.h includes
"third_party/skia/include/utils/SkPaintFilterCanvas.h", which includes SkTLazy,
so wouldn't you get it from there?

   // TODO(fmalita): with the new onFilter() API we could override alpha even
   // when the original paint is null; is this something we should do?
   if (*paint) {
     if (alpha_ < 255)
       paint->writable()->setAlpha(alpha_);
 
     if (disable_image_filtering_)
       paint->writable()->setFilterQuality(kNone_SkFilterQuality);
   }
 
   return true;
 }
 
 void OpacityFilterCanvas::onDrawPicture(const SkPicture* picture,
                                         const SkMatrix* matrix,
                                         const SkPaint* paint) {
   SkTCopyOnFirstWrite<SkPaint> filteredPaint(paint);
   if (this->onFilter(&filteredPaint, kPicture_Type)) {
     // Unfurl pictures in order to filter nested paints.
     this->SkCanvas::onDrawPicture(picture, matrix, filteredPaint);
   }
 }
 
 }  // namespace skia