Return unique_ptrs from CFX_DIBitmap::Clone().

core/fpdfapi/render/fpdf_render_loadimage.cpp

Index: core/fpdfapi/render/fpdf_render_loadimage.cpp
diff --git a/core/fpdfapi/render/fpdf_render_loadimage.cpp b/core/fpdfapi/render/fpdf_render_loadimage.cpp
index d797b061350481a94583683632ebe0b1c70d3177..f690f688b191bf4bfc79f33bb71d83335c072dea 100644
--- a/core/fpdfapi/render/fpdf_render_loadimage.cpp
+++ b/core/fpdfapi/render/fpdf_render_loadimage.cpp
@@ -132,16 +132,6 @@ CPDF_DIBSource::~CPDF_DIBSource() {
   }
 }
 
-CFX_DIBitmap* CPDF_DIBSource::GetBitmap() const {
-  return m_pCachedBitmap ? m_pCachedBitmap.get() : Clone();
-}
-
-void CPDF_DIBSource::ReleaseBitmap(CFX_DIBitmap* pBitmap) const {
-  if (pBitmap && pBitmap != m_pCachedBitmap.get()) {
-    delete pBitmap;
-  }
-}
-
 bool CPDF_DIBSource::Load(CPDF_Document* pDoc,
                           const CPDF_Stream* pStream,
                           CPDF_DIBSource** ppMask,