Switch various ValueTypeToString()s to base::Value::GetTypeName().

tools/json_schema_compiler/util.h

Index: tools/json_schema_compiler/util.h
diff --git a/tools/json_schema_compiler/util.h b/tools/json_schema_compiler/util.h
index 8b852739f6a1078b5fca50e38612fdd49e4bf6b1..d7862cea4f63a6682cbe25aebc8bbe0a67eae08e 100644
--- a/tools/json_schema_compiler/util.h
+++ b/tools/json_schema_compiler/util.h
@@ -207,13 +207,9 @@ std::unique_ptr<base::Value> CreateValueFromArray(const std::vector<T>& from) {
 template <class T>
 std::unique_ptr<base::Value> CreateValueFromOptionalArray(
     const std::unique_ptr<std::vector<T>>& from) {
-  if (from)
-    return CreateValueFromArray(*from);
-  return nullptr;
+  return from ? CreateValueFromArray(*from) : nullptr;
 }
 
-std::string ValueTypeToString(base::Value::Type type);
-
 }  // namespace util
 }  // namespace json_schema_compiler