Remove CFX_Deletable

BUILD.gn

 # Copyright 2016 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build_overrides/v8.gni")
 import("//testing/test.gni")
 import("pdfium.gni")
 
 config("pdfium_common_config") {
   cflags = []
@@ skipping 500 matching lines @@
     "core/fxcodec/codec/ccodec_jpxmodule.h",
     "core/fxcodec/codec/ccodec_scanlinedecoder.h",
     "core/fxcodec/codec/codec_int.h",
     "core/fxcodec/codec/fx_codec.cpp",
     "core/fxcodec/codec/fx_codec_fax.cpp",
     "core/fxcodec/codec/fx_codec_flate.cpp",
     "core/fxcodec/codec/fx_codec_icc.cpp",
     "core/fxcodec/codec/fx_codec_jbig.cpp",
     "core/fxcodec/codec/fx_codec_jpeg.cpp",
     "core/fxcodec/codec/fx_codec_jpx_opj.cpp",
+    "core/fxcodec/include/JBig2_DocumentContext.h",
     "core/fxcodec/include/fx_codec.h",
     "core/fxcodec/include/fx_codec_def.h",
     "core/fxcodec/jbig2/JBig2_ArithDecoder.cpp",
     "core/fxcodec/jbig2/JBig2_ArithDecoder.h",
     "core/fxcodec/jbig2/JBig2_ArithIntDecoder.cpp",
     "core/fxcodec/jbig2/JBig2_ArithIntDecoder.h",
     "core/fxcodec/jbig2/JBig2_BitStream.cpp",
     "core/fxcodec/jbig2/JBig2_BitStream.h",
     "core/fxcodec/jbig2/JBig2_Context.cpp",
     "core/fxcodec/jbig2/JBig2_Context.h",
@@ skipping 1074 matching lines @@
 }
 
 if (pdf_is_standalone) {
   source_set("samples") {
     testonly = true
     deps = [
       "//samples",
     ]
   }
 }