Move CPDF_Document code into cpdf_document.cpp.

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_config") {
   cflags = []
@@ skipping 289 matching lines @@
     "core/fpdfapi/fpdf_cmaps/Korea1/KSCpc-EUC-H_0.cpp",
     "core/fpdfapi/fpdf_cmaps/Korea1/UniKS-UCS2-H_1.cpp",
     "core/fpdfapi/fpdf_cmaps/Korea1/UniKS-UCS2-V_1.cpp",
     "core/fpdfapi/fpdf_cmaps/Korea1/UniKS-UTF16-H_0.cpp",
     "core/fpdfapi/fpdf_cmaps/Korea1/cmaps_korea1.cpp",
     "core/fpdfapi/fpdf_cmaps/cmap_int.h",
     "core/fpdfapi/fpdf_cmaps/fpdf_cmaps.cpp",
     "core/fpdfapi/fpdf_edit/cpdf_pagecontentgenerator.cpp",
     "core/fpdfapi/fpdf_edit/editint.h",
     "core/fpdfapi/fpdf_edit/fpdf_edit_create.cpp",
-    "core/fpdfapi/fpdf_edit/fpdf_edit_doc.cpp",
     "core/fpdfapi/fpdf_edit/include/cpdf_creator.h",
     "core/fpdfapi/fpdf_edit/include/cpdf_pagecontentgenerator.h",
     "core/fpdfapi/fpdf_font/cpdf_cidfont.cpp",
     "core/fpdfapi/fpdf_font/cpdf_cidfont.h",
     "core/fpdfapi/fpdf_font/cpdf_font.cpp",
     "core/fpdfapi/fpdf_font/cpdf_fontencoding.cpp",
     "core/fpdfapi/fpdf_font/cpdf_simplefont.cpp",
     "core/fpdfapi/fpdf_font/cpdf_simplefont.h",
     "core/fpdfapi/fpdf_font/cpdf_truetypefont.cpp",
     "core/fpdfapi/fpdf_font/cpdf_truetypefont.h",
@@ skipping 1387 matching lines @@
 }
 
 if (pdf_is_standalone) {
   source_set("samples") {
     testonly = true
     deps = [
       "//samples",
     ]
   }
 }