Make cc::DrawingDisplayItem hold a const SkPicture.

This lets us remove const_cast<SkPicture*> from callers (i.e. Blink) which
hold SkPicture through const pointers.

CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel

Review URL: https://codereview.chromium.org/1564233005

Cr-Commit-Position: refs/heads/master@{#368444}

3 files changed, 7 insertions, 8 deletions

diff --git a/cc/blink/web_display_item_list_impl.cc b/cc/blink/web_display_item_list_impl.cc
index c46e8a0..c9d8de7 100644
--- a/cc/blink/web_display_item_list_impl.cc
+++ b/cc/blink/web_display_item_list_impl.cc
@@ -54,10 +54,9 @@ void WebDisplayItemListImpl::appendDrawingItem(
     const SkPicture* picture) {
   if (display_item_list_->RetainsIndividualDisplayItems()) {
     display_item_list_->CreateAndAppendItem<cc::DrawingDisplayItem>(
-        visual_rect, skia::SharePtr(const_cast<SkPicture*>(picture)));
+        visual_rect, skia::SharePtr(picture));
   } else {
-    cc::DrawingDisplayItem item(
-        skia::SharePtr(const_cast<SkPicture*>(picture)));
+    cc::DrawingDisplayItem item(skia::SharePtr(picture));
     display_item_list_->RasterIntoCanvas(item);
   }
 }
diff --git a/cc/playback/drawing_display_item.cc b/cc/playback/drawing_display_item.cc
index 78f26fe..36181ae 100644
--- a/cc/playback/drawing_display_item.cc
+++ b/cc/playback/drawing_display_item.cc
@@ -25,7 +25,7 @@ namespace cc {
 
 DrawingDisplayItem::DrawingDisplayItem() {}
 
-DrawingDisplayItem::DrawingDisplayItem(skia::RefPtr<SkPicture> picture) {
+DrawingDisplayItem::DrawingDisplayItem(skia::RefPtr<const SkPicture> picture) {
   SetNew(std::move(picture));
 }
 
@@ -51,7 +51,7 @@ DrawingDisplayItem::DrawingDisplayItem(const DrawingDisplayItem& item) {
 DrawingDisplayItem::~DrawingDisplayItem() {
 }
 
-void DrawingDisplayItem::SetNew(skia::RefPtr<SkPicture> picture) {
+void DrawingDisplayItem::SetNew(skia::RefPtr<const SkPicture> picture) {
   picture_ = std::move(picture);
 }
 
diff --git a/cc/playback/drawing_display_item.h b/cc/playback/drawing_display_item.h
index 9e8f110..225bda4 100644
--- a/cc/playback/drawing_display_item.h
+++ b/cc/playback/drawing_display_item.h
@@ -21,7 +21,7 @@ namespace cc {
 class CC_EXPORT DrawingDisplayItem : public DisplayItem {
  public:
   DrawingDisplayItem();
-  explicit DrawingDisplayItem(skia::RefPtr<SkPicture> picture);
+  explicit DrawingDisplayItem(skia::RefPtr<const SkPicture> picture);
   explicit DrawingDisplayItem(const proto::DisplayItem& proto);
   explicit DrawingDisplayItem(const DrawingDisplayItem& item);
   ~DrawingDisplayItem() override;
@@ -40,9 +40,9 @@ class CC_EXPORT DrawingDisplayItem : public DisplayItem {
   void CloneTo(DrawingDisplayItem* item) const;
 
  private:
-  void SetNew(skia::RefPtr<SkPicture> picture);
+  void SetNew(skia::RefPtr<const SkPicture> picture);
 
-  skia::RefPtr<SkPicture> picture_;
+  skia::RefPtr<const SkPicture> picture_;
 };
 
 }  // namespace cc