Add action for each button on opt-in IME menu.

chrome/browser/chromeos/input_method/mock_input_method_manager.cc

Index: chrome/browser/chromeos/input_method/mock_input_method_manager.cc
diff --git a/chrome/browser/chromeos/input_method/mock_input_method_manager.cc b/chrome/browser/chromeos/input_method/mock_input_method_manager.cc
index 46b038ed8ca4f11df728dbc09c1e0f6cb11de4be..322a5866541dc758d22d640c7d49e7b7806ca8fb 100644
--- a/chrome/browser/chromeos/input_method/mock_input_method_manager.cc
+++ b/chrome/browser/chromeos/input_method/mock_input_method_manager.cc
@@ -255,5 +255,11 @@ void MockInputMethodManager::NotifyImeMenuItemsChanged(
 
 void MockInputMethodManager::MaybeNotifyImeMenuActivationChanged() {}
 
+void MockInputMethodManager::OverrideKeyboardRef(const std::string& keyset) {}
+
+bool MockInputMethodManager::IsEmojiHandwritingVoiceOnImeMenuEnabled() {
+  return false;
+}
+
 }  // namespace input_method
 }  // namespace chromeos