Add header files that were missing from BUILD.gn.

ui/gfx/BUILD.gn

 # Copyright 2014 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/ui.gni")
 import("//testing/test.gni")
 import("//testing/libfuzzer/fuzzer_test.gni")
 
 if (is_android) {
   import("//build/config/android/config.gni")
@@ skipping 286 matching lines @@
     sources += [ "platform_font_linux.cc" ]
     set_sources_assignment_filter(sources_assignment_filter)
   }
 
   # iOS.
   if (is_ios) {
     sources -= [
       "codec/jpeg_codec.cc",
       "codec/jpeg_codec.h",
     ]
+    set_sources_assignment_filter([])
+    sources += [ "scoped_cg_context_save_gstate_mac.h" ]
+    set_sources_assignment_filter(sources_assignment_filter)
   } else {
     deps += [ "//third_party:jpeg" ]
   }
 
   # Android.
   if (is_android) {
     if (use_aura) {
       sources -= [ "canvas_notimplemented.cc" ]
       sources += [ "font_fallback_android.cc" ]
     } else {
@@ skipping 401 matching lines @@
 
 fuzzer_test("color_transform_fuzztest") {
   sources = [
     "color_transform_fuzzer.cc",
   ]
   deps = [
     ":gfx",
   ]
   libfuzzer_options = [ "max_len=1024" ]
 }