Take advantage of implicit std::unique_ptr<>(nulltpr_t) ctor.

core/fpdfapi/font/cpdf_font.cpp

 // Copyright 2016 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #include "core/fpdfapi/font/cpdf_font.h"
 
 #include <memory>
 #include <vector>
@@ skipping 325 matching lines @@
   } else if (type == "Type3") {
     pFont.reset(new CPDF_Type3Font);
   } else if (type == "Type0") {
     pFont.reset(new CPDF_CIDFont);
   } else {
     pFont.reset(new CPDF_Type1Font);
   }
   pFont->m_pFontDict = pFontDict;
   pFont->m_pDocument = pDoc;
   pFont->m_BaseFont = pFontDict->GetStringFor("BaseFont");
-  return pFont->Load() ? std::move(pFont) : std::unique_ptr<CPDF_Font>();
+  return pFont->Load() ? std::move(pFont) : nullptr;
 }
 
 uint32_t CPDF_Font::GetNextChar(const FX_CHAR* pString,
                                 int nStrLen,
                                 int& offset) const {
   if (offset < 0 || nStrLen < 1) {
     return 0;
   }
   uint8_t ch = offset < nStrLen ? pString[offset++] : pString[nStrLen - 1];
   return static_cast<uint32_t>(ch);
@@ skipping 110 matching lines @@
   if (fallbackFont < 0 ||
       fallbackFont >= pdfium::CollectionSize<int>(m_FontFallbacks)) {
     return -1;
   }
   int glyph =
       FXFT_Get_Char_Index(m_FontFallbacks[fallbackFont]->GetFace(), charcode);
   if (glyph == 0 || glyph == 0xffff)
     return -1;
   return glyph;
 }