Use smart pointers for graphics device classes

core/fxcrt/include/fx_memory.h

 // Copyright 2014 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
 
 #ifndef CORE_FXCRT_INCLUDE_FX_MEMORY_H_
 #define CORE_FXCRT_INCLUDE_FX_MEMORY_H_
 
 #include "core/fxcrt/include/fx_system.h"
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
 // For external C libraries to malloc through PDFium. These may return nullptr.
 void* FXMEM_DefaultAlloc(size_t byte_size, int flags);
 void* FXMEM_DefaultRealloc(void* pointer, size_t new_size, int flags);
 void FXMEM_DefaultFree(void* pointer, int flags);
 
 #ifdef __cplusplus
 }  // extern "C"
 
 #include <stdlib.h>
 #include <limits>
+#include <memory>
 #include <new>
 
 NEVER_INLINE void FX_OutOfMemoryTerminate();
 
 inline void* FX_SafeRealloc(void* ptr, size_t num_members, size_t member_size) {
   if (num_members < std::numeric_limits<size_t>::max() / member_size) {
     return realloc(ptr, num_members * member_size);
   }
   return nullptr;
 }
@@ skipping 57 matching lines @@
 struct FxFreeDeleter {
   inline void operator()(void* ptr) const { FX_Free(ptr); }
 };
 
 // Used with std::unique_ptr to Release() objects that can't be deleted.
 template <class T>
 struct ReleaseDeleter {
   inline void operator()(T* ptr) const { ptr->Release(); }
 };
 
+// Used to help transfer ownership of a raw pointer to std::unique_ptr.
+template <typename T>
+std::unique_ptr<T> WrapUnique(T* ptr) {
+  return std::unique_ptr<T>(ptr);
+}
+
 class CFX_Deletable {
  public:
   virtual ~CFX_Deletable() {}
 };
 
 #endif  // __cplusplus
 
 #endif  // CORE_FXCRT_INCLUDE_FX_MEMORY_H_