cc: Gather and lock/unlock SkDiscardablePixelRefs instead of skia::LazyPixelRefs.

cc/resources/picture_pile_impl.h

Index: cc/resources/picture_pile_impl.h
diff --git a/cc/resources/picture_pile_impl.h b/cc/resources/picture_pile_impl.h
index 180dba258ee2f5b347627dcdfc08a31e9b884684..2bc9da80bd757b52b4b353d9fb52facedb2a1d8b 100644
--- a/cc/resources/picture_pile_impl.h
+++ b/cc/resources/picture_pile_impl.h
@@ -87,8 +87,8 @@ class CC_EXPORT PicturePileImpl : public PicturePileBase {
                      const PicturePileImpl* picture_pile);
     ~PixelRefIterator();
 
-    skia::LazyPixelRef* operator->() const { return *pixel_ref_iterator_; }
-    skia::LazyPixelRef* operator*() const { return *pixel_ref_iterator_; }
+    SkPixelRef* operator->() const { return *pixel_ref_iterator_; }
+    SkPixelRef* operator*() const { return *pixel_ref_iterator_; }
     PixelRefIterator& operator++();
     operator bool() const { return pixel_ref_iterator_; }