bring pdfium file in sync with chrome, fix mac build

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 641 matching lines @@
     "core/fxge/android/fpf_skiafont.cpp",
     "core/fxge/android/fpf_skiafont.h",
     "core/fxge/android/fpf_skiafontmgr.cpp",
     "core/fxge/android/fpf_skiafontmgr.h",
     "core/fxge/android/fpf_skiamodule.cpp",
     "core/fxge/android/fpf_skiamodule.h",
     "core/fxge/android/fx_android_font.cpp",
     "core/fxge/android/fx_android_font.h",
     "core/fxge/android/fx_android_imp.cpp",
     "core/fxge/apple/apple_int.h",
-    "core/fxge/apple/fx_apple_platform.cpp",
     "core/fxge/apple/fx_mac_imp.cpp",
     "core/fxge/apple/fx_quartz_device.cpp",
     "core/fxge/dib/dib_int.h",
     "core/fxge/dib/fx_dib_composite.cpp",
     "core/fxge/dib/fx_dib_convert.cpp",
     "core/fxge/dib/fx_dib_engine.cpp",
     "core/fxge/dib/fx_dib_main.cpp",
     "core/fxge/dib/fx_dib_transform.cpp",
     "core/fxge/fontdata/chromefontdata/FoxitDingbats.cpp",
     "core/fxge/fontdata/chromefontdata/FoxitFixed.cpp",
@@ skipping 38 matching lines @@
 
   if (pdf_use_skia) {
     sources += [ "core/fxge/skia/fx_skia_device.cpp" ]
     deps = [
       "//skia",
     ]
   } else {
     sources += [
       "core/fxge/agg/fx_agg_driver.cpp",
       "core/fxge/agg/fx_agg_driver.h",
+      "core/fxge/apple/fx_apple_platform.cpp",
     ]
     deps = [
       "third_party:fx_agg",
     ]
   }
 
   if (is_win) {
     sources += [
       "core/fxge/win32/dwrite_int.h",
       "core/fxge/win32/fx_win32_device.cpp",
@@ skipping 853 matching lines @@
 }
 
 if (pdf_is_standalone) {
   source_set("samples") {
     testonly = true
     deps = [
       "//samples",
     ]
   }
 }