Remove foxitlib.h and foxitxfa.h and IWYU.

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 755 matching lines @@
     ]
     configs -= [ "//build/config/compiler:chromium_code" ]
     configs += [
       ":pdfium_config",
       "//build/config/compiler:no_chromium_code",
     ]
   }
 
   static_library("xfa") {
     sources = [
-      "xfa/include/foxitxfa.h",
       "xfa/include/fwl/adapter/fwl_adapternative.h",
       "xfa/include/fwl/adapter/fwl_adapterthreadmgr.h",
       "xfa/include/fwl/adapter/fwl_adaptertimermgr.h",
       "xfa/include/fwl/adapter/fwl_adapterwidgetmgr.h",
       "xfa/include/fwl/adapter/fwl_sdadapterimp.h",
       "xfa/include/fwl/basewidget/fwl_barcode.h",
       "xfa/include/fwl/basewidget/fwl_caret.h",
       "xfa/include/fwl/basewidget/fwl_checkbox.h",
       "xfa/include/fwl/basewidget/fwl_combobox.h",
       "xfa/include/fwl/basewidget/fwl_datetimepicker.h",
@@ skipping 147 matching lines @@
       "xfa/src/fgas/src/layout/fx_textbreak.h",
       "xfa/src/fgas/src/layout/fx_unicode.cpp",
       "xfa/src/fgas/src/layout/fx_unicode.h",
       "xfa/src/fgas/src/localization/fx_datetime.cpp",
       "xfa/src/fgas/src/localization/fx_locale.cpp",
       "xfa/src/fgas/src/localization/fx_localeimp.h",
       "xfa/src/fgas/src/localization/fx_localemgr.cpp",
       "xfa/src/fgas/src/localization/fx_localemgr.h",
       "xfa/src/fgas/src/xml/fx_sax_imp.cpp",
       "xfa/src/fgas/src/xml/fx_sax_imp.h",
-      "xfa/src/foxitlib.h",
       "xfa/src/fwl/src/basewidget/fwl_barcodeimp.cpp",
       "xfa/src/fwl/src/basewidget/fwl_caretimp.cpp",
       "xfa/src/fwl/src/basewidget/fwl_checkboximp.cpp",
       "xfa/src/fwl/src/basewidget/fwl_comboboximp.cpp",
       "xfa/src/fwl/src/basewidget/fwl_datetimepickerimp.cpp",
       "xfa/src/fwl/src/basewidget/fwl_editimp.cpp",
       "xfa/src/fwl/src/basewidget/fwl_formproxyimp.cpp",
       "xfa/src/fwl/src/basewidget/fwl_listboximp.cpp",
       "xfa/src/fwl/src/basewidget/fwl_monthcalendarimp.cpp",
       "xfa/src/fwl/src/basewidget/fwl_pictureboximp.cpp",
@@ skipping 549 matching lines @@
       "//v8:v8_libplatform",
     ]
     include_dirs += [
       "//v8",
       "//v8/include",
     ]
     configs += [ "//v8:external_startup_data" ]
   }
   configs += [ ":pdfium_config" ]
 }