Remove fde.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 825 matching lines @@
       "xfa/include/fwl/theme/scrollbartp.h",
       "xfa/include/fwl/theme/utils.h",
       "xfa/include/fwl/theme/widgettp.h",
       "xfa/include/fxbarcode/BC_BarCode.h",
       "xfa/include/fxfa/fxfa.h",
       "xfa/include/fxfa/fxfa_basic.h",
       "xfa/include/fxfa/fxfa_objectacc.h",
       "xfa/include/fxfa/fxfa_widget.h",
       "xfa/include/fxgraphics/fx_graphics.h",
       "xfa/include/fxjse/fxjse.h",
-      "xfa/src/fdp/include/fde.h",
       "xfa/src/fdp/include/fde_brs.h",
       "xfa/src/fdp/include/fde_css.h",
       "xfa/src/fdp/include/fde_img.h",
       "xfa/src/fdp/include/fde_mem.h",
       "xfa/src/fdp/include/fde_pen.h",
       "xfa/src/fdp/include/fde_psr.h",
       "xfa/src/fdp/include/fde_pth.h",
       "xfa/src/fdp/include/fde_rdr.h",
       "xfa/src/fdp/include/fde_rdv.h",
       "xfa/src/fdp/include/fde_tto.h",
@@ skipping 653 matching lines @@
       "//v8:v8_libplatform",
     ]
     include_dirs += [
       "//v8",
       "//v8/include",
     ]
     configs += [ "//v8:external_startup_data" ]
   }
   configs += [ ":pdfium_config" ]
 }