Remove CPDF_PSEngine::num_operators().

It is no longer called.

Change-Id: I19cb62fca1f161ef4911e07dffb1881bce933658
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/120253
Reviewed-by: Thomas Sepez <tsepez@google.com>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>
diff --git a/core/fpdfapi/page/cpdf_psengine.h b/core/fpdfapi/page/cpdf_psengine.h
index 908c701..2a298dd 100644
--- a/core/fpdfapi/page/cpdf_psengine.h
+++ b/core/fpdfapi/page/cpdf_psengine.h
@@ -7,7 +7,6 @@
 #ifndef CORE_FPDFAPI_PAGE_CPDF_PSENGINE_H_
 #define CORE_FPDFAPI_PAGE_CPDF_PSENGINE_H_
 
-#include <stddef.h>
 #include <stdint.h>
 
 #include <array>
@@ -96,7 +95,6 @@
 
   // These methods are exposed for testing.
   void AddOperatorForTesting(ByteStringView word);
-  size_t num_operators() const { return m_Operators.size(); }
   const std::unique_ptr<CPDF_PSOP>& last_operator() {
     return m_Operators.back();
   }