Add an option in language settings for activating the IME menu.

chrome/browser/resources/options/language_options.html

Index: chrome/browser/resources/options/language_options.html
diff --git a/chrome/browser/resources/options/language_options.html b/chrome/browser/resources/options/language_options.html
index 58dea62609870923e1f480b5b7709402c1409eea..587db26fdc52d3c71ed40e293f125752f2f07097 100644
--- a/chrome/browser/resources/options/language_options.html
+++ b/chrome/browser/resources/options/language_options.html
@@ -114,6 +114,12 @@
       <a is="action-link" id="edit-custom-dictionary-button"
           class="standalone-action-link"
           i18n-content="languageDictionaryOverlayTitle"></a>
+      <div>
+        <label>
+          <input type="checkbox" id="activate-system-ime-menu">
+          <span i18n-content="activateSystemImeMenu"></span>
+        </label>
+      </div>
 </if>
 <if expr="not chromeos and not is_macosx">
       <div class="checkbox">