Remove the SkCanvas comment API

include/core/SkPicture.h

Index: include/core/SkPicture.h
diff --git a/include/core/SkPicture.h b/include/core/SkPicture.h
index 30e410cca35f406535589130722231543bc6abba..473c6b7c1e128a99227102e580faed29d9e48c6c 100644
--- a/include/core/SkPicture.h
+++ b/include/core/SkPicture.h
@@ -179,6 +179,9 @@ private:
     static_assert(MIN_PICTURE_VERSION <= 41,
                   "Remove kFontFileName and related code from SkFontDescriptor.cpp.");
 
+    static_assert(MIN_PICTURE_VERSION <= 42,
+                  "Remove COMMENT API handlers from SkPicturePlayback.cpp");
+
     static bool IsValidPictInfo(const SkPictInfo& info);
     static SkPicture* Forwardport(const SkPictInfo&, const SkPictureData*);