chromeos: make app-list not layout search-box when closed

As part of https://chromium-review.googlesource.com/c/chromium/src/+/1547051
InvalidateLayout() was changed to result in a Layout() at a later date. This
means there may be an additional Layout() called. In particular, the app-list
now attempts to layout the search-box when closed, which triggers the search-box
to go off screen. The fix is to not layout the search box if closed.

BUG=949368
TEST=see bug

Change-Id: I810ba64a0d44cfedb4f1746697c78b74a303526d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1559887Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/master@{#649271}

ash/app_list/views/contents_view.cc

@@ -295,6 +295,11 @@ bool ContentsView::IsShowingEmbeddedAssistantUI() const {
 }
 
 void ContentsView::UpdatePageBounds() {
+  // No need to do anything while closed. To layout while closed may result in
+  // the search-box going offscreen.
+  if (app_list_view_->app_list_state() == AppListViewState::CLOSED)
+    return;
+
   // The bounds calculations will potentially be mid-transition (depending on
   // the state of the PaginationModel).
   int current_page = std::max(0, pagination_model_.selected_page());
@@ -326,7 +331,6 @@ void ContentsView::UpdatePageBounds() {
       page->OnAnimationUpdated(progress, current_state, target_state);
   }
 
-  // Update the search box.
   UpdateSearchBox(progress, current_state, target_state);
 
   // Update the expand arrow view's opacity.