Get rid of NULLs in fpdfsdk/

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 NULL.
+// 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 <new>
@@ skipping 27 matching lines @@
 inline void* FX_ReallocOrDie(void* ptr,
                              size_t num_members,
                              size_t member_size) {
   if (void* result = FX_SafeRealloc(ptr, num_members, member_size)) {
     return result;
   }
   FX_OutOfMemoryTerminate();  // Never returns.
   return nullptr;             // Suppress compiler warning.
 }
 
-// Never returns NULL.
+// Never returns nullptr.
 #define FX_Alloc(type, size) (type*) FX_AllocOrDie(size, sizeof(type))
 #define FX_Alloc2D(type, w, h) (type*) FX_AllocOrDie2D(w, h, sizeof(type))
 #define FX_Realloc(type, ptr, size) \
   (type*) FX_ReallocOrDie(ptr, size, sizeof(type))
 
-// May return NULL.
+// May return nullptr.
 #define FX_TryAlloc(type, size) (type*) calloc(size, sizeof(type))
 #define FX_TryRealloc(type, ptr, size) \
   (type*) FX_SafeRealloc(ptr, size, sizeof(type))
 
 #define FX_Free(ptr) free(ptr)
 
 // The FX_ArraySize(arr) macro returns the # of elements in an array arr.
 // The expression is a compile-time constant, and therefore can be
 // used in defining new arrays, for example.  If you use FX_ArraySize on
 // a pointer by mistake, you will get a compile-time error.
@@ skipping 20 matching lines @@
 };
 
 class CFX_Deletable {
  public:
   virtual ~CFX_Deletable() {}
 };
 
 #endif  // __cplusplus
 
 #endif  // CORE_FXCRT_INCLUDE_FX_MEMORY_H_