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

chrome/browser/resources/options/language_options.html

 <div id="languagePage" class="page" hidden>
   <div class="close-button"></div>
   <h1 i18n-content="languagePage"></h1>
   <div class="content-area">
     <div id="notification">
       <span>&nbsp;</span>
       <span class="link"><span class="link-color"></span></span>
     </div>
     <div class="language-options-header">
       <span i18n-content="addLanguageInstructions"></span>
@@ skipping 96 matching lines @@
 </if>
       </div>
     </div>
     <div class="language-options-footer">
 <if expr="chromeos">
       <div i18n-content="switchInputMethodsHint"></div>
       <div i18n-content="selectPreviousInputMethodHint"></div>
       <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">
         <label id="enable-spellcheck-container">
           <input id="enable-spellcheck" pref="browser.enable_spellchecking"
               metric="Options_SpellCheck" type="checkbox">
           <span i18n-content="enableSpellCheck"></span>
         </label>
         <a is="action-link" id="edit-custom-dictionary-button"
             i18n-content="languageDictionaryOverlayTitle" hidden></a>
       </div>
 </if>
     </div>
   </div>
   <div class="action-area">
     <div class="button-strip">
       <button id="language-confirm" class="default-button" i18n-content="done">
       </button>
     </div>
   </div>
 </div>