combobox: don't animate state changes in TransparentButton

ui/views/controls/combobox/combobox.cc

Index: ui/views/controls/combobox/combobox.cc
diff --git a/ui/views/controls/combobox/combobox.cc b/ui/views/controls/combobox/combobox.cc
index bb8623a26f631e183c6b62289581e95a1336fc19..12057eb53c8c0f58c103c548b5f51b8500edefe4 100644
--- a/ui/views/controls/combobox/combobox.cc
+++ b/ui/views/controls/combobox/combobox.cc
@@ -119,6 +119,7 @@ class TransparentButton : public CustomButton {
     SetAnimationDuration(LabelButton::kHoverAnimationDurationMs);

[Evan Stade, 2016/09/09 18:37:13]

why is this here?

[Elly Fong-Jones, 2016/09/12 11:46:40]

Your guess is as good as mine. It was added in the implementation of "action
style" comboboxes in https://codereview.chromium.org/59383003 and it seems like
this specific line was copied verbatim from LabelButton's constructor. I would
rather like to remove this entire class.

[Evan Stade, 2016/09/12 14:51:17]

It seems the line you're adding defeats the purpose of SetAnimationDuration. I
think you're breaking PaintButtons below (only used for action style comboboxes,
but one of those still exists for now). You should probably either set the
animation duration or set animate false depending on the style of combobox.

     SetFocusBehavior(FocusBehavior::NEVER);
     set_notify_action(PlatformStyle::kMenuNotifyActivationAction);
+    set_animate_on_state_change(false);
 
     if (UseMd()) {
       SetInkDropMode(PlatformStyle::kUseRipples ? InkDropMode::ON