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

chrome/browser/chromeos/extensions/input_method_api.h

Index: chrome/browser/chromeos/extensions/input_method_api.h
diff --git a/chrome/browser/chromeos/extensions/input_method_api.h b/chrome/browser/chromeos/extensions/input_method_api.h
index f8cd11905eefcda296082e26bc25c8b775471468..eb7ed82a304c0cf3775f8a7824c42a6d48289586 100644
--- a/chrome/browser/chromeos/extensions/input_method_api.h
+++ b/chrome/browser/chromeos/extensions/input_method_api.h
@@ -14,6 +14,7 @@
 namespace chromeos {
 class ExtensionDictionaryEventRouter;
 class ExtensionInputMethodEventRouter;
+class ExtensionImeMenuEventRouter;
 }
 
 namespace extensions {
@@ -136,6 +137,8 @@ class InputMethodAPI : public BrowserContextKeyedAPI,
   static const char kOnDictionaryChanged[];
   static const char kOnDictionaryLoaded[];
   static const char kOnInputMethodChanged[];
+  static const char kOnImeMenuActivated[];
+  static const char kOnImeMenuDeactivated[];
 
   explicit InputMethodAPI(content::BrowserContext* context);
   ~InputMethodAPI() override;
@@ -169,6 +172,7 @@ class InputMethodAPI : public BrowserContextKeyedAPI,
       input_method_event_router_;
   scoped_ptr<chromeos::ExtensionDictionaryEventRouter>
       dictionary_event_router_;
+  scoped_ptr<chromeos::ExtensionImeMenuEventRouter> ime_menu_event_router_;
 
   DISALLOW_COPY_AND_ASSIGN(InputMethodAPI);
 };