Replace SkTLazy with base::Optional

cc/playback/image_hijack_canvas.cc

Index: cc/playback/image_hijack_canvas.cc
diff --git a/cc/playback/image_hijack_canvas.cc b/cc/playback/image_hijack_canvas.cc
index f0fc139ed6d32b821141bdcdc41c368e2e498a1b..94dd39867420822f629bbc9036dc31fd74511fdd 100644
--- a/cc/playback/image_hijack_canvas.cc
+++ b/cc/playback/image_hijack_canvas.cc
@@ -2,11 +2,12 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "base/optional.h"

[bungeman-chromium, 2016/04/27 18:15:05]

This include should go with the second set of includes.
https://google.github.io/styleguide/cppguide.html#Names_and_Order_of_Includes

+
 #include "cc/playback/image_hijack_canvas.h"
 
 #include "cc/playback/discardable_image_map.h"
 #include "cc/tiles/image_decode_controller.h"
-#include "third_party/skia/include/core/SkTLazy.h"
 
 namespace cc {
 namespace {
@@ -33,8 +34,8 @@ class ScopedDecodedImageLock {
             image_decode_controller_->GetDecodedImageForDraw(draw_image_)) {
     DCHECK(draw_image_.image()->isLazyGenerated());
     if (paint)
-      decoded_paint_.set(*paint)->setFilterQuality(
-          decoded_draw_image_.filter_quality());
+      (decoded_paint_ = *paint)

[vmpstr, 2016/04/27 18:01:01]

Can you separate this into two separate steps, please?

+          ->setFilterQuality(decoded_draw_image_.filter_quality());
   }
 
   ~ScopedDecodedImageLock() {
@@ -43,14 +44,15 @@ class ScopedDecodedImageLock {
   }
 
   const DecodedDrawImage& decoded_image() const { return decoded_draw_image_; }
-  const SkPaint* decoded_paint() const { return decoded_paint_.getMaybeNull(); }
+  const SkPaint* decoded_paint() const {
+    return decoded_paint_ ? &(*decoded_paint_) : NULL;

[vmpstr, 2016/04/27 18:01:02]

nullptr

+  }
 
  private:
   ImageDecodeController* image_decode_controller_;
   DrawImage draw_image_;
   DecodedDrawImage decoded_draw_image_;
-  // TODO(fmalita): use base::Optional when it becomes available
-  SkTLazy<SkPaint> decoded_paint_;
+  base::Optional<SkPaint> decoded_paint_;
 };
 
 }  // namespace