Convert spellcheck to a buildflag header.

build/config/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/allocator.gni")
 import("//build/config/chrome_build.gni")
 import("//build/config/chromecast_build.gni")
 import("//build/config/crypto.gni")
 import("//build/config/dcheck_always_on.gni")
 import("//build/config/features.gni")
@@ skipping 53 matching lines @@
   defines = [ "V8_DEPRECATION_WARNINGS" ]
   if (enable_notifications) {
     defines += [ "ENABLE_NOTIFICATIONS" ]
   }
   if (enable_plugins) {
     defines += [ "ENABLE_PLUGINS=1" ]
   }
   if (enable_pdf) {
     defines += [ "ENABLE_PDF=1" ]
   }
-  if (enable_spellcheck) {
-    defines += [ "ENABLE_SPELLCHECK=1" ]
-  }
-  if (use_browser_spellchecker) {
-    defines += [ "USE_BROWSER_SPELLCHECKER=1" ]
-  }
   if (dcheck_always_on) {
     defines += [ "DCHECK_ALWAYS_ON=1" ]
   }
   if (use_udev) {
     # TODO(brettw) should probably be "=1".
     defines += [ "USE_UDEV" ]
   }
   if (ui_compositor_image_transport) {
     # TODO(brettw) should probably be "=1".
     defines += [ "UI_COMPOSITOR_IMAGE_TRANSPORT" ]
@@ skipping 340 matching lines @@
       # file doesn't exist, no error will be generated (probably MS tested this
       # case but forgot the other one?). To reproduce this error, do a build,
       # then delete the precompile.c.obj file, then build again.
       cflags_c = [ "/wd4206" ]
     } else if (is_mac) {
       precompiled_header = "build/precompile.h"
       precompiled_source = "//build/precompile.h"
     }
   }
 }