[svg] Add 'filter' presentation attribute and parsing

Not yet used by anything.

Bug: skia:10841
Change-Id: I6ed0a434cf670d73f06eaf0bbfe70d727ffe4950
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/330617
Commit-Queue: Tyler Denniston <tdenniston@google.com>
Reviewed-by: Florin Malita <fmalita@chromium.org>
diff --git a/modules/svg/include/SkSVGValue.h b/modules/svg/include/SkSVGValue.h
index 0040179..8e70d9d 100644
--- a/modules/svg/include/SkSVGValue.h
+++ b/modules/svg/include/SkSVGValue.h
@@ -22,6 +22,7 @@
         kColor,
         kDashArray,
         kFillRule,
+        kFilter,
         kFontFamily,
         kFontSize,
         kFontStyle,
@@ -85,6 +86,7 @@
 using SkSVGClipValue         = SkSVGWrapperValue<SkSVGClip         , SkSVGValue::Type::kClip      >;
 using SkSVGColorValue        = SkSVGWrapperValue<SkSVGColorType    , SkSVGValue::Type::kColor     >;
 using SkSVGFillRuleValue     = SkSVGWrapperValue<SkSVGFillRule     , SkSVGValue::Type::kFillRule  >;
+using SkSVGFilterValue       = SkSVGWrapperValue<SkSVGFilterType   , SkSVGValue::Type::kFilter    >;
 using SkSVGLengthValue       = SkSVGWrapperValue<SkSVGLength       , SkSVGValue::Type::kLength    >;
 using SkSVGPathValue         = SkSVGWrapperValue<SkPath            , SkSVGValue::Type::kPath      >;
 using SkSVGTransformValue    = SkSVGWrapperValue<SkSVGTransformType, SkSVGValue::Type::kTransform >;