Split fpdf_text_int into classes

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 520 matching lines @@
     "core/fpdfapi/fpdf_render/include/cpdf_textrenderer.h",
     "core/fpdfapi/fpdf_render/render_int.h",
     "core/fpdfapi/include/cpdf_modulemgr.h",
     "core/fpdfapi/include/cpdf_pagerendercontext.h",
   ]
   configs += [ ":pdfium_core_config" ]
 }
 
 static_library("fpdftext") {
   sources = [
-    "core/fpdftext/fpdf_text_int.cpp",
+    "core/fpdftext/cpdf_linkextract.cpp",
+    "core/fpdftext/cpdf_textpage.cpp",
+    "core/fpdftext/cpdf_textpagefind.cpp",
     "core/fpdftext/include/cpdf_linkextract.h",
     "core/fpdftext/include/cpdf_textpage.h",
     "core/fpdftext/include/cpdf_textpagefind.h",
     "core/fpdftext/text_int.h",
     "core/fpdftext/unicodenormalizationdata.cpp",
     "core/fpdftext/unicodenormalizationdata.h",
   ]
   configs += [ ":pdfium_core_config" ]
 }
 
@@ skipping 1147 matching lines @@
 }
 
 if (pdf_is_standalone) {
   source_set("samples") {
     testonly = true
     deps = [
       "//samples",
     ]
   }
 }