cc: Delete unused DisplayItem::GetPicture func

cc/playback/drawing_display_item.cc

 // 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.
 
 #include "cc/playback/drawing_display_item.h"
 
 #include <stddef.h>
 
 #include <string>
 
@@ skipping 24 matching lines @@
   item.CloneTo(this);
 }
 
 DrawingDisplayItem::~DrawingDisplayItem() {
 }
 
 void DrawingDisplayItem::SetNew(sk_sp<const SkPicture> picture) {
   picture_ = std::move(picture);
 }
 
-sk_sp<const SkPicture> DrawingDisplayItem::GetPicture() const {
-  return picture_;
-}
-
 DISABLE_CFI_PERF
 void DrawingDisplayItem::Raster(SkCanvas* canvas,
                                 SkPicture::AbortCallback* callback) const {
   if (canvas->quickReject(picture_->cullRect()))
     return;
 
   // SkPicture always does a wrapping save/restore on the canvas, so it is not
   // necessary here.
   if (callback)
     picture_->playback(canvas, callback);
@@ skipping 34 matching lines @@
 size_t DrawingDisplayItem::ExternalMemoryUsage() const {
   return SkPictureUtils::ApproximateBytesUsed(picture_.get());
 }
 
 DISABLE_CFI_PERF
 int DrawingDisplayItem::ApproximateOpCount() const {
   return picture_->approximateOpCount();
 }
 
 }  // namespace cc