Delete SkFlattenable::Type (part 1)

This should allow me to delete uses of SkFlattenable::Type in Chrome.
Then I'll follow up with the full delete.
https://codereview.chromium.org/1834303003/

TBR=reed@google.com

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1861013002

Review URL: https://codereview.chromium.org/1861013002
diff --git a/include/core/SkFlattenableSerialization.h b/include/core/SkFlattenableSerialization.h
index ffb1b5a..c5ff06a 100644
--- a/include/core/SkFlattenableSerialization.h
+++ b/include/core/SkFlattenableSerialization.h
@@ -14,6 +14,6 @@
 
 SK_API SkData* SkValidatingSerializeFlattenable(SkFlattenable*);
 SK_API SkFlattenable* SkValidatingDeserializeFlattenable(const void* data, size_t size,
-                                                         SkFlattenable::Type type);
+        SkFlattenable::Type type = SkFlattenable::kSkUnused_Type);
 
 #endif
diff --git a/src/core/SkValidatingReadBuffer.cpp b/src/core/SkValidatingReadBuffer.cpp
index ad4b6c4..c80192f 100644
--- a/src/core/SkValidatingReadBuffer.cpp
+++ b/src/core/SkValidatingReadBuffer.cpp
@@ -222,20 +222,14 @@
     return this->validate((size <= SK_MaxU32) && fReader.isAvailable(static_cast<uint32_t>(size)));
 }
 
-SkFlattenable* SkValidatingReadBuffer::readFlattenable(SkFlattenable::Type type) {
+SkFlattenable* SkValidatingReadBuffer::readFlattenable(SkFlattenable::Type) {
     SkString name;
     this->readString(&name);
     if (fError) {
         return nullptr;
     }
 
-    // Is this the type we wanted ?
     const char* cname = name.c_str();
-    SkFlattenable::Type baseType;
-    if (!SkFlattenable::NameToType(cname, &baseType) || (baseType != type)) {
-        return nullptr;
-    }
-
     SkFlattenable::Factory factory = SkFlattenable::NameToFactory(cname);
     if (nullptr == factory) {
         return nullptr; // writer failed to give us the flattenable