Revert "Revert "Change how vertex/instance attributes are handled in geometry processors.""

This reverts commit 5045e501d2aec23e5f1e4b46346033ac3202c6b0.

TBR=csmartdalton@google.com

Change-Id: Ifbf5f1d8f8ef340fdc69653e931b6d68d4bf0854
Reviewed-on: https://skia-review.googlesource.com/135862
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
diff --git a/src/gpu/GrPathProcessor.h b/src/gpu/GrPathProcessor.h
index 72e5168..6893e88 100644
--- a/src/gpu/GrPathProcessor.h
+++ b/src/gpu/GrPathProcessor.h
@@ -38,6 +38,18 @@
     virtual bool isPathRendering() const override { return true; }
 
 private:
+    const Attribute& onVertexAttribute(int i) const final {
+        SK_ABORT("No vertex attributes");
+        static constexpr Attribute kBogus;
+        return kBogus;
+    }
+
+    const Attribute& onInstanceAttribute(int i) const final {
+        SK_ABORT("No instanced attributes");
+        static constexpr Attribute kBogus;
+        return kBogus;
+    }
+
     GrPathProcessor(GrColor, const SkMatrix& viewMatrix, const SkMatrix& localMatrix);
 
     GrColor fColor;