[Promise Icons] Stop showing accessible name in Launcher item tooltip

Currently, Launcher promise items have tooltips which show the
accessible name (i.e. text announced by the screenreader). UX has
explicitly advised against this, so this CL aims to fix this behaviour.

This CL removes the line that sets the tooltip_text to the accessible
name. In regular Launcher items, display_name is always the same as the
full_name, so the logic was never triggered anyway. However, in promise
app items, the display_name always differs from the full_name
(accessible name) which results in the accessible name being set for
the tooltip. Hence, we will remove the tooltip_text_ attribute and let
the tooltip fallback to default behaviour of showing the item title.

Bug: b/305140229
Change-Id: I0f3101cac5fc3ec3691d59ec46bce00e1ac2accc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4976359
Commit-Queue: Vivian Pao <vpao@google.com>
Reviewed-by: Toni Barzic <tbarzic@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1216714}

ash/app_list/views/app_list_item_view.cc

@@ -1124,8 +1124,6 @@ void AppListItemView::SetItemName(const std::u16string& display_name,
     title_->SetText(display_name);
   }
 
-  tooltip_text_ = display_name == full_name ? std::u16string() : full_name;
-
   // Use full name for accessibility.
   SetAccessibleName(
       is_folder_ ? l10n_util::GetStringFUTF16(
@@ -1716,7 +1714,6 @@ std::u16string AppListItemView::GetTooltipText(const gfx::Point& p) const {
   // tooltip, so we only temporarily enable it to get the tooltip text from the
   // label, then disable it again.
   title_->SetHandlesTooltips(true);
-  title_->SetTooltipText(tooltip_text_);
   std::u16string tooltip = title_->GetTooltipText(p);
   title_->SetHandlesTooltips(false);
   if (new_install_dot_ && new_install_dot_->GetVisible() && !is_folder_) {

ash/app_list/views/app_list_item_view.h

@@ -539,8 +539,6 @@ class ASH_EXPORT AppListItemView : public views::Button,
   // Whether `item_menu_model_adapter_` was shown via key event.
   bool menu_show_initiated_from_key_ = false;
 
-  std::u16string tooltip_text_;
-
   // A timer to defer showing drag UI when mouse is pressed.
   base::OneShotTimer mouse_drag_timer_;
   // A timer to defer showing drag UI when the app item is touch pressed.