Add MD ink drop ripple to app list button

ui/views/controls/button/custom_button.cc

Index: ui/views/controls/button/custom_button.cc
diff --git a/ui/views/controls/button/custom_button.cc b/ui/views/controls/button/custom_button.cc
index 62b96997799c96688f0ddc5e7f7d85c90370e16c..85dc33627b1d853aebe03296affa86e9b96f3618 100644
--- a/ui/views/controls/button/custom_button.cc
+++ b/ui/views/controls/button/custom_button.cc
@@ -163,15 +163,17 @@ bool CustomButton::OnMousePressed(const ui::MouseEvent& event) {
 bool CustomButton::OnMouseDragged(const ui::MouseEvent& event) {
   if (state_ != STATE_DISABLED) {
     const bool should_enter_pushed = ShouldEnterPushedState(event);
+    const bool should_show_pending =
+        should_enter_pushed && notify_action_ == NOTIFY_ON_RELEASE && !InDrag();
     if (HitTestPoint(event.location())) {
       SetState(should_enter_pushed ? STATE_PRESSED : STATE_HOVERED);
-      if (!InDrag() && should_enter_pushed &&
+      if (should_show_pending &&
           ink_drop()->GetTargetInkDropState() == views::InkDropState::HIDDEN) {
         AnimateInkDrop(views::InkDropState::ACTION_PENDING, &event);
       }
     } else {
       SetState(STATE_NORMAL);
-      if (!InDrag() && should_enter_pushed &&
+      if (should_show_pending &&
           ink_drop()->GetTargetInkDropState() ==
               views::InkDropState::ACTION_PENDING) {
         AnimateInkDrop(views::InkDropState::HIDDEN, &event);