Return unique_ptrs from CFX_DIBitmap::Clone().

core/fpdfapi/font/cpdf_type3char.cpp

Index: core/fpdfapi/font/cpdf_type3char.cpp
diff --git a/core/fpdfapi/font/cpdf_type3char.cpp b/core/fpdfapi/font/cpdf_type3char.cpp
index e5b7450a0a30eb2d87be999cc88c68b69ad68e6c..41ab82471753fed0c69466db9ba21e642ebb01eb 100644
--- a/core/fpdfapi/font/cpdf_type3char.cpp
+++ b/core/fpdfapi/font/cpdf_type3char.cpp
@@ -32,7 +32,7 @@ bool CPDF_Type3Char::LoadBitmap(CPDF_RenderContext* pContext) {
   std::unique_ptr<CFX_DIBSource> pSource(
       pPageObj->AsImage()->GetImage()->LoadDIBSource());
   if (pSource)
-    m_pBitmap.reset(pSource->Clone());
+    m_pBitmap = pSource->Clone();
   m_pForm.reset();
   return true;
 }