Add MD ink drop ripple to app list button

ash/sysui/app_list_presenter_mus.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ash/sysui/app_list_presenter_mus.h"
 
 #include "services/shell/public/cpp/connector.h"
 
 namespace ash {
 namespace {
@@ skipping 27 matching lines @@
   ConnectIfNeeded();
   presenter_->Dismiss();
 }
 
 void AppListPresenterMus::ToggleAppList(int64_t display_id) {
   display_id = GetMusDisplayId(display_id);
   ConnectIfNeeded();
   presenter_->ToggleAppList(display_id);
 }
 
+bool AppListPresenterMus::IsVisible() const {
+  return false;
+}
+
 bool AppListPresenterMus::GetTargetVisibility() const {
   // TODO(mfomitchev): we have GetTargetVisibility() in mojom, but this
   // shouldn't be a synchronous method. We should go through the call sites and
   // either teach them to use a callback, or perhaps use a visibility observer.
   //  NOTIMPLEMENTED();
   return false;
 }
 
 bool AppListPresenterMus::ConnectIfNeeded() {
   if (HasConnection(&presenter_))
     return true;
   connector_->ConnectToInterface("exe:chrome", &presenter_);
   CHECK(HasConnection(&presenter_))
       << "Could not connect to app_list::mojom::AppListPresenter.";
   return true;
 }
 
 }  // namespace ash