Switch from nonstd::unique_ptr to std::unique_ptr.

core/include/fxge/fx_font.h

Index: core/include/fxge/fx_font.h
diff --git a/core/include/fxge/fx_font.h b/core/include/fxge/fx_font.h
index 8234458fe5c799f3eca8e07bbe9cbd6e5291cd5e..d6e3359c61635e72ba2c49517e581e57a827c1ff 100644
--- a/core/include/fxge/fx_font.h
+++ b/core/include/fxge/fx_font.h
@@ -8,10 +8,10 @@
 #define CORE_INCLUDE_FXGE_FX_FONT_H_
 
 #include <map>
+#include <memory>
 
 #include "core/include/fxcrt/fx_system.h"
 #include "fx_dib.h"
-#include "third_party/base/nonstd_unique_ptr.h"
 
 typedef struct FT_FaceRec_* FXFT_Face;
 typedef void* FXFT_Library;
@@ -212,7 +212,7 @@ class CFX_FontMgr {
   FXFT_Library GetFTLibrary() const { return m_FTLibrary; }
 
  private:
-  nonstd::unique_ptr<CFX_FontMapper> m_pBuiltinMapper;
+  std::unique_ptr<CFX_FontMapper> m_pBuiltinMapper;
   std::map<CFX_ByteString, CTTFontDesc*> m_FaceMap;
   FXFT_Library m_FTLibrary;
 };