Fix overflow caught by ASAN.
BUG=skia:
Review URL: https://codereview.chromium.org/1498923002
diff --git a/src/codec/SkBmpRLECodec.h b/src/codec/SkBmpRLECodec.h
index fcf910d..df2a97d 100644
--- a/src/codec/SkBmpRLECodec.h
+++ b/src/codec/SkBmpRLECodec.h
@@ -90,6 +90,7 @@
SkSampler* getSampler(bool createIfNecessary) override;
SkAutoTUnref<SkColorTable> fColorTable; // owned
+ // fNumColors is the number specified in the header, or 0 if not present in the header.
const uint32_t fNumColors;
const uint32_t fBytesPerColor;
const uint32_t fOffset;