Convert spellcheck to a buildflag header.

components/spellcheck/renderer/hunspell_engine.cc

 // Copyright (c) 2012 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.
 
 #include "components/spellcheck/renderer/hunspell_engine.h"
 
 #include <stddef.h>
 #include <algorithm>
 #include <iterator>
 #include <utility>
 
 #include "base/files/memory_mapped_file.h"
 #include "base/time/time.h"
 #include "components/spellcheck/common/spellcheck_common.h"
 #include "components/spellcheck/common/spellcheck_messages.h"
+#include "components/spellcheck/spellcheck_build_features.h"
 #include "content/public/renderer/render_thread.h"
 #include "third_party/hunspell/src/hunspell/hunspell.hxx"
 
 using content::RenderThread;
 
 namespace {
   // Maximum length of words we actually check.
   // 64 is the observed limits for OSX system checker.
   const size_t kMaxCheckedLen = 64;
 
   // Maximum length of words we provide suggestions for.
   // 24 is the observed limits for OSX system checker.
   const size_t kMaxSuggestLen = 24;
 
   static_assert(kMaxCheckedLen <= size_t(MAXWORDLEN),
                 "MaxCheckedLen too long");
   static_assert(kMaxSuggestLen <= kMaxCheckedLen,
                 "MaxSuggestLen too long");
 }  // namespace
 
-#if !defined(USE_BROWSER_SPELLCHECKER)
+#if !BUILDFLAG(USE_BROWSER_SPELLCHECKER)
 SpellingEngine* CreateNativeSpellingEngine() {
   return new HunspellEngine();
 }
 #endif
 
 HunspellEngine::HunspellEngine()
     : hunspell_enabled_(false),
       initialized_(false),
       dictionary_requested_(false) {
   // Wait till we check the first word before doing any initializing.
@@ skipping 84 matching lines @@
   // Don't initialize if hunspell is disabled.
   if (file_.IsValid())
     InitializeHunspell();
 
   return !initialized_;
 }
 
 bool HunspellEngine::IsEnabled() {
   return hunspell_enabled_;
 }