Convert spellcheck to a buildflag header.

chrome/browser/chrome_content_browser_client.cc

Index: chrome/browser/chrome_content_browser_client.cc
diff --git a/chrome/browser/chrome_content_browser_client.cc b/chrome/browser/chrome_content_browser_client.cc
index ce9507def3a49c33c13c5bdf4f876c55c6833eea..33d141ed87a2871c9d4cad6d1f5eda5e5970795a 100644
--- a/chrome/browser/chrome_content_browser_client.cc
+++ b/chrome/browser/chrome_content_browser_client.cc
@@ -139,6 +139,7 @@
 #include "components/rappor/rappor_utils.h"
 #include "components/security_interstitials/core/ssl_error_ui.h"
 #include "components/signin/core/common/profile_management_switches.h"
+#include "components/spellcheck/spellcheck_build_features.h"
 #include "components/startup_metric_utils/browser/startup_metric_host_impl.h"
 #include "components/translate/core/common/translate_switches.h"
 #include "components/url_formatter/url_fixer.h"
@@ -318,11 +319,11 @@
 #include "chrome/browser/plugins/flash_download_interception.h"
 #endif
 
-#if defined(ENABLE_SPELLCHECK)
+#if BUILDFLAG(ENABLE_SPELLCHECK)
 #include "chrome/browser/spellchecker/spellcheck_message_filter.h"
 #endif
 
-#if defined(USE_BROWSER_SPELLCHECKER)
+#if BUILDFLAG(USE_BROWSER_SPELLCHECKER)
 #include "components/spellcheck/browser/spellcheck_message_filter_platform.h"
 #endif
 
@@ -1033,10 +1034,10 @@ void ChromeContentBrowserClient::RenderProcessWillLaunch(
 #if BUILDFLAG(ENABLE_PRINTING)
   host->AddFilter(new printing::PrintingMessageFilter(id, profile));
 #endif
-#if defined(ENABLE_SPELLCHECK)
+#if BUILDFLAG(ENABLE_SPELLCHECK)
   host->AddFilter(new SpellCheckMessageFilter(id));
 #endif
-#if defined(USE_BROWSER_SPELLCHECKER)
+#if BUILDFLAG(USE_BROWSER_SPELLCHECKER)
   host->AddFilter(new SpellCheckMessageFilterPlatform(id));
 #endif
   host->AddFilter(new ChromeNetBenchmarkingMessageFilter(profile, context));