Make CPDF_Dictionary methods take CFX_ByteString arguments

This will help avoid duplicate allocation of CFX_ByteStrings
when the caller already has one.  It may seem counter-intuitive
that requiring the caller to pass an allocated CFX_ByteString
rather than a static CFX_ByteStringC would improve the situation,
but due to the idiosyncrasies of std::map, the CPDF_Dictionary
methods must always do an allocation under the covers which
can't be avoided.

The changed callers in this CL are places where we would
previously demote to CFX_ByteStringC and then allocate a
a duplicate CFX_ByteString in the dictionary method.

Review URL: https://codereview.chromium.org/1889863002

1 files changed, 1 insertions, 1 deletions

diff --git a/core/fpdfdoc/doc_basic.cpp b/core/fpdfdoc/doc_basic.cpp
index 6d6e5c234f..a3e94cb033 100644
--- a/core/fpdfdoc/doc_basic.cpp
+++ b/core/fpdfdoc/doc_basic.cpp
@@ -482,7 +482,7 @@ CFX_WideString CPDF_PageLabel::GetLabel(int nPage) const {
       if (pLabel->KeyExist("P")) {
         wsLabel += pLabel->GetUnicodeTextBy("P");
       }
-      CFX_ByteString bsNumberingStyle = pLabel->GetStringBy("S", NULL);
+      CFX_ByteString bsNumberingStyle = pLabel->GetStringBy("S", nullptr);
       int nLabelNum = nPage - n + pLabel->GetIntegerBy("St", 1);
       CFX_WideString wsNumPortion =
           _GetLabelNumPortion(nLabelNum, bsNumberingStyle);