Revert "Remove FX_Alloc() null checks now that it can't return NULL."

core/src/fpdfapi/fpdf_edit/fpdf_edit_create.cpp

 // 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
 
 #include "../../../include/fpdfapi/fpdf_serial.h"
 #include "editint.h"
 #define PDF_OBJECTSTREAM_MAXLENGTH      (256 * 1024)
 #define PDF_XREFSTREAM_MAXSIZE          10000
@@ skipping 397 matching lines @@
         return TRUE;
     }
     if (pHandler == NULL) {
         m_pData = (FX_LPBYTE)src_data;
         m_dwSize = src_size;
         m_bNewBuf = FALSE;
         return TRUE;
     }
     m_dwSize = pHandler->EncryptGetSize(objnum, 0, src_data, src_size);
     m_pData = FX_Alloc(FX_BYTE, m_dwSize);
+    if(!m_pData) {
+        return FALSE;
+    }
     pHandler->EncryptContent(objnum, 0, src_data, src_size, m_pData, m_dwSize);
     m_bNewBuf = TRUE;
     return TRUE;
 }
 CPDF_Encryptor::~CPDF_Encryptor()
 {
     if (m_bNewBuf) {
         FX_Free(m_pData);
     }
 }
@@ skipping 1699 matching lines @@
     m_bNewCrypto = FALSE;
     if (!m_bStandardSecurity) {
         return;
     }
     if (m_pEncryptDict) {
         m_pEncryptDict->Release();
         m_pEncryptDict = NULL;
     }
     m_bStandardSecurity = FALSE;
 }