[Android WebView] Add functionality to enable features and enable the spellcheck feature.

android_webview/lib/main/aw_main_delegate.cc

Index: android_webview/lib/main/aw_main_delegate.cc
diff --git a/android_webview/lib/main/aw_main_delegate.cc b/android_webview/lib/main/aw_main_delegate.cc
index f45591858285f225af2a88a869db69bc27b5d84c..78445f3c0dc958c8a8ad0ece5bd4443977d459ff 100644
--- a/android_webview/lib/main/aw_main_delegate.cc
+++ b/android_webview/lib/main/aw_main_delegate.cc
@@ -8,6 +8,7 @@
 
 #include "android_webview/browser/aw_content_browser_client.h"
 #include "android_webview/browser/browser_view_renderer.h"
+#include "android_webview/browser/command_line_helper.h"
 #include "android_webview/browser/deferred_gpu_command_service.h"
 #include "android_webview/browser/scoped_allow_wait_for_legacy_web_view_api.h"
 #include "android_webview/common/aw_descriptors.h"
@@ -31,6 +32,7 @@
 #include "base/threading/thread_restrictions.h"
 #include "cc/base/switches.h"
 #include "components/crash/content/app/breakpad_linux.h"
+#include "components/spellcheck/common/spellcheck_features.h"
 #include "content/public/browser/android/browser_media_player_manager_register.h"
 #include "content/public/browser/browser_main_runner.h"
 #include "content/public/browser/browser_thread.h"
@@ -137,6 +139,9 @@ bool AwMainDelegate::BasicStartupComplete(int* exit_code) {
     cl->AppendSwitch(switches::kDisableRendererBackgrounding);
   }
 
+  CommandLineHelper::AddEnabledFeature(
+      *cl, spellcheck::kAndroidSpellCheckerNonLowEnd.name);
+
   return false;
 }