Add safe FX_Alloc2D() macro

core/include/fxcrt/fx_basic.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 _FX_BASIC_H_
 #define _FX_BASIC_H_
 
 #include "fx_memory.h"
@@ skipping 1436 matching lines @@
     }
 
     void                        Append(FX_INT32 nStart, FX_INT32 nCount)
     {
         if (nStart < 0) {
             return;
         }
         while (nCount > 0) {
             FX_INT32 temp_count = FX_MIN(nCount, FX_DATALIST_LENGTH);
             DataList list;
-            list.data = FX_Alloc(FX_BYTE, temp_count * unit);
-            if (!list.data) {
-                break;
-            }
+            list.data = FX_Alloc2D(FX_BYTE, temp_count, unit);
             list.start = nStart;
             list.count = temp_count;
             Append(list);
             nCount -= temp_count;
             nStart += temp_count;
         }
     }
 
     FX_LPBYTE           GetAt(FX_INT32 nIndex)
     {
@@ skipping 136 matching lines @@
     FX_FLOAT c;
     FX_FLOAT d;
     FX_FLOAT e;
     FX_FLOAT f;
     FX_FLOAT g;
     FX_FLOAT h;
     FX_FLOAT i;
 };
 
 #endif