Simplify flattening to just write enough to call the factory

src/effects/SkCornerPathEffect.cpp

Index: src/effects/SkCornerPathEffect.cpp
diff --git a/src/effects/SkCornerPathEffect.cpp b/src/effects/SkCornerPathEffect.cpp
index 5b61e06df804f1152498b1bea49904db7f310905..06558826bf5d4f3a921e7984a82c5b218aba26a7 100644
--- a/src/effects/SkCornerPathEffect.cpp
+++ b/src/effects/SkCornerPathEffect.cpp
@@ -128,11 +128,16 @@ DONE:
     return true;
 }
 
+SkFlattenable* SkCornerPathEffect::CreateProc(SkReadBuffer& buffer) {
+    return SkCornerPathEffect::Create(buffer.readScalar());
+}
+
 void SkCornerPathEffect::flatten(SkWriteBuffer& buffer) const {
-    this->INHERITED::flatten(buffer);
     buffer.writeScalar(fRadius);
 }
 
+#ifdef SK_SUPPORT_LEGACY_DEEPFLATTENING
 SkCornerPathEffect::SkCornerPathEffect(SkReadBuffer& buffer) {
     fRadius = buffer.readScalar();
 }
+#endif