Pass CFX_Matrix by const-ref in fxbarcode/

-- Comment one suspicious line while at it.

Change-Id: I67385abcd88f1ffccca4e12517806865e04f75d0
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/79350
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>
diff --git a/fxbarcode/cbc_code128.cpp b/fxbarcode/cbc_code128.cpp
index 83c8abe..b4dc117 100644
--- a/fxbarcode/cbc_code128.cpp
+++ b/fxbarcode/cbc_code128.cpp
@@ -52,7 +52,7 @@
 }
 
 bool CBC_Code128::RenderDevice(CFX_RenderDevice* device,
-                               const CFX_Matrix* matrix) {
+                               const CFX_Matrix& matrix) {
   return GetOnedCode128Writer()->RenderDeviceResult(
       device, matrix, m_renderContents.AsStringView());
 }