simplify code in SkRecords.h

src/core/SkRecordPattern.h

Index: src/core/SkRecordPattern.h
diff --git a/src/core/SkRecordPattern.h b/src/core/SkRecordPattern.h
index ecc61b3aaa1cabeab38889fad5989635ce5de74b..d9568b360a97c8925f77802c6a0eef4ef66f9e84 100644
--- a/src/core/SkRecordPattern.h
+++ b/src/core/SkRecordPattern.h
@@ -41,7 +41,6 @@ private:
 
 // Matches any command that draws, and stores its paint.
 class IsDraw {
-    SK_CREATE_MEMBER_DETECTOR(paint);
 public:
     IsDraw() : fPaint(nullptr) {}
 
@@ -49,19 +48,19 @@ public:
     type* get() { return fPaint; }
 
     template <typename T>
-    SK_WHEN(HasMember_paint<T>, bool) operator()(T* draw) {
+    SK_WHEN(T::kTags & kDraw_Tag, bool) operator()(T* draw) {
         fPaint = AsPtr(draw->paint);
         return true;
     }
 
-    template <typename T>
-    SK_WHEN(!HasMember_paint<T>, bool) operator()(T*) {
+    bool operator()(DrawDrawable*) {
+        static_assert(DrawDrawable::kTags & kDraw_Tag, "");
         fPaint = nullptr;
-        return false;
+        return true;
     }
 
-    // SaveLayer has an SkPaint named paint, but it's not a draw.
-    bool operator()(SaveLayer*) {
+    template <typename T>
+    SK_WHEN(!(T::kTags & kDraw_Tag), bool) operator()(T* draw) {
         fPaint = nullptr;
         return false;
     }