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 50cffe9286fcc6ac39dfada288b17e2d92949d50..71e79559462e424762a3c0f0cea43fde3588373f 100644
--- a/ui/views/controls/button/custom_button.cc
+++ b/ui/views/controls/button/custom_button.cc
@@ -162,16 +162,18 @@ bool CustomButton::OnMousePressed(const ui::MouseEvent& event) {
 
 bool CustomButton::OnMouseDragged(const ui::MouseEvent& event) {
   if (state_ != STATE_DISABLED) {
-    bool should_enter_pushed = ShouldEnterPushedState(event);
+    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);
       }
     } else {
       SetState(STATE_NORMAL);
-      if (!InDrag() && should_enter_pushed &&
+      if (should_show_pending &&
           ink_drop()->GetTargetInkDropState() ==
               views::InkDropState::ACTION_PENDING) {
         AnimateInkDrop(views::InkDropState::HIDDEN);