Avoid duplicate bytestring construction in IsValidNumericDictionaryValue()

Force callers to create a bytestring arg rather than doing it twice
implicitly at line 31 and 33 from the c-style string.

Change-Id: Ie3cde0daa8d01773dba2baa90a2ca43a886e1aa1
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/86691
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>
diff --git a/core/fpdfapi/parser/cpdf_linearized_header.cpp b/core/fpdfapi/parser/cpdf_linearized_header.cpp
index 2c927c7..1ba724e 100644
--- a/core/fpdfapi/parser/cpdf_linearized_header.cpp
+++ b/core/fpdfapi/parser/cpdf_linearized_header.cpp
@@ -25,7 +25,7 @@
 
 template <class T>
 bool IsValidNumericDictionaryValue(const CPDF_Dictionary* pDict,
-                                   const char* key,
+                                   const ByteString& key,
                                    T min_value,
                                    bool must_exist = true) {
   if (!pDict->KeyExist(key))