Remove CFX_CountRef::IsNull in favor of operator bool

core/fpdfapi/fpdf_page/cpdf_shadingobject.cpp

Index: core/fpdfapi/fpdf_page/cpdf_shadingobject.cpp
diff --git a/core/fpdfapi/fpdf_page/cpdf_shadingobject.cpp b/core/fpdfapi/fpdf_page/cpdf_shadingobject.cpp
index b2eb5e642c34a44631ae95b64c8b673ef3c54e97..968c53bc073b71c8367f6a93d2cb3ccd4e884a66 100644
--- a/core/fpdfapi/fpdf_page/cpdf_shadingobject.cpp
+++ b/core/fpdfapi/fpdf_page/cpdf_shadingobject.cpp
@@ -35,12 +35,12 @@ CPDF_PageObject::Type CPDF_ShadingObject::GetType() const {
 }
 
 void CPDF_ShadingObject::Transform(const CFX_Matrix& matrix) {
-  if (!m_ClipPath.IsNull()) {
+  if (m_ClipPath) {
     m_ClipPath.GetModify();
     m_ClipPath.Transform(matrix);
   }
   m_Matrix.Concat(matrix);
-  if (!m_ClipPath.IsNull()) {
+  if (m_ClipPath) {
     CalcBoundingBox();
   } else {
     matrix.TransformRect(m_Left, m_Right, m_Top, m_Bottom);
@@ -60,9 +60,8 @@ const CPDF_ShadingObject* CPDF_ShadingObject::AsShading() const {
 }
 
 void CPDF_ShadingObject::CalcBoundingBox() {
-  if (m_ClipPath.IsNull()) {
+  if (!m_ClipPath)
     return;
-  }
   CFX_FloatRect rect = m_ClipPath.GetClipBox();
   m_Left = rect.left;
   m_Bottom = rect.bottom;