Fix left padding for StackedNotificationBar

Change-Id: Ie83fa6664ead99583212c5d303615f8fed7de1d9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1864356Reviewed-by: Tim Song <tengs@chromium.org>
Commit-Queue: Ahmed Mehfooz <amehfooz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#707098}

ash/system/message_center/stacked_notification_bar.cc

@@ -127,8 +127,12 @@ StackedNotificationBar::StackedNotificationBar(
               IDS_ASH_MESSAGE_CENTER_EXPAND_ALL_NOTIFICATIONS_BUTTON_LABEL))) {
   SetVisible(false);
 
+  int left_padding = features::IsUnifiedMessageCenterRefactorEnabled()
+                         ? 0
+                         : kStackingNotificationClearAllButtonPadding.left();
   auto* layout = SetLayoutManager(std::make_unique<views::BoxLayout>(
-      views::BoxLayout::Orientation::kHorizontal));
+      views::BoxLayout::Orientation::kHorizontal,
+      gfx::Insets(0, left_padding, 0, 0)));
   layout->set_cross_axis_alignment(
       views::BoxLayout::CrossAxisAlignment::kStretch);