bring pdfium file in sync with chrome, fix mac build

skia/BUILD.gn

 # Copyright (c) 2013 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/config/features.gni")
 import("//build/config/ui.gni")
 import("//testing/test.gni")
 
 if (current_cpu == "arm") {
   import("//build/config/arm.gni")
@@ skipping 312 matching lines @@
       "//third_party/skia/src/ports/SkTypeface_win_dw.cpp",
     ]
   }
   if (!is_android) {
     sources -= [
       "//third_party/skia/src/ports/SkFontMgr_android.cpp",
       "//third_party/skia/src/ports/SkFontMgr_android_factory.cpp",
       "//third_party/skia/src/ports/SkFontMgr_android_parser.cpp",
     ]
   }
-  if (!is_mac) {
-    sources -= [ "//third_party/skia/src/ports/SkFontHost_mac.cpp" ]
-  }
-
-  if (!is_linux && !is_android && !is_win) {
+  if (!is_linux && !is_android && !is_win && !is_mac) {
     sources -= [
       "//third_party/skia/src/ports/SkFontHost_FreeType.cpp",
       "//third_party/skia/src/ports/SkFontHost_FreeType_common.cpp",
       "//third_party/skia/src/ports/SkFontMgr_custom.cpp",
       "//third_party/skia/src/ports/SkFontMgr_custom_empty_factory.cpp",
     ]
   }
 
   if (is_clang && !is_nacl) {
     # Skia won't compile with some of the more strict clang warnings.
@@ skipping 196 matching lines @@
 
   configs -= [ "//build/config/compiler:chromium_code" ]
   configs += [
     ":skia_config",
     ":skia_library_config",
     "//build/config/compiler:no_chromium_code",
   ]
 
   visibility = [ ":skia" ]
 }