Remove CFX_CountRef::IsNull in favor of operator bool

core/fpdfapi/fpdf_page/cpdf_pathobject.cpp

Index: core/fpdfapi/fpdf_page/cpdf_pathobject.cpp
diff --git a/core/fpdfapi/fpdf_page/cpdf_pathobject.cpp b/core/fpdfapi/fpdf_page/cpdf_pathobject.cpp
index b62a5bd25aed421622d58c9e783b04a46be40e94..0055d6a1332080d012ded43a8c1cccffe780df5e 100644
--- a/core/fpdfapi/fpdf_page/cpdf_pathobject.cpp
+++ b/core/fpdfapi/fpdf_page/cpdf_pathobject.cpp
@@ -43,9 +43,8 @@ const CPDF_PathObject* CPDF_PathObject::AsPath() const {
 }
 
 void CPDF_PathObject::CalcBoundingBox() {
-  if (m_Path.IsNull()) {
+  if (!m_Path)
     return;
-  }
   CFX_FloatRect rect;
   FX_FLOAT width = m_GraphState.GetObject()->m_LineWidth;
   if (m_bStroke && width != 0) {