1 files changed, 9 insertions, 0 deletions
diff --git a/lazy/SkDiscardablePixelRef.h b/lazy/SkDiscardablePixelRef.h
index 4b669383..3367096c 100644
--- a/lazy/SkDiscardablePixelRef.h
+++ b/lazy/SkDiscardablePixelRef.h
@@ -13,6 +13,15 @@
 #include "SkImageInfo.h"
 #include "SkPixelRef.h"
 
+/**
+ *  A PixelRef backed by SkDiscardableMemory, with the ability to
+ *  re-generate the pixels (via a SkImageGenerator) if the DM is
+ *  purged.
+ *
+ *  Since SkColorTable is reference-counted, we do not support indexed
+ *  color with this class; there would be no way for the discardable
+ *  memory system to unref the color table.
+ */
 class SkDiscardablePixelRef : public SkPixelRef {
 public:
     SK_DECLARE_UNFLATTENABLE_OBJECT()