cros: Fix rounded corners on shelf on first tablet mode startup

Since CL 1737730, AppList visibility is now correct in tablet mode.

After this change, bugs have surfaced with the shelf background.
To fix this, modify HomeLauncherGestureHandler so we no longer notify
observers that the animation has completed before clearing state.

The specific issue was that
HomeLauncherGestureHandler::IsDragInProgress returns true when
observers are notified of home launcher animation completion.

So, fix this, then check HomeLauncherGestureHandler::IsDragInProgress
to more accurately determine the proper shelf background.

Also check for widget visibility, not activation, because the widget
is not activated in tablet mode when shown.

Bug: 990995

Change-Id: I560a6db4c045dbbc802f18b43266e2c1f2f19e1a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1746915
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Reviewed-by: Sammie Quon <sammiequon@chromium.org>
Commit-Queue: Alex Newcomer <newcomer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#687306}

ash/app_list/presenter/app_list_presenter_impl.cc

@@ -107,6 +107,8 @@ void AppListPresenterImpl::Show(int64_t display_id,
     SetView(view);
   }
   delegate_->ShowForDisplay(display_id);
+  if (delegate_->IsTabletMode())
+    home_launcher_shown_ = true;
 
   NotifyTargetVisibilityChanged(GetTargetVisibility());
   NotifyVisibilityChanged(GetTargetVisibility(), display_id);
@@ -299,7 +301,9 @@ void AppListPresenterImpl::OnTabletModeChanged(bool started) {
       DCHECK(IsVisible());
       view_->OnTabletModeChanged(true);
     }
-    home_launcher_shown_ = GetWindow() && GetWindow()->HasFocus();
+    // The AppList widget is shown without being focused in tablet mode, so
+    // check for visibility, not focus.
+    home_launcher_shown_ = GetWindow() && GetWindow()->IsVisible();
   } else {
     if (IsVisible())
       view_->OnTabletModeChanged(false);

ash/home_screen/home_launcher_gesture_handler.cc

@@ -492,10 +492,11 @@ void HomeLauncherGestureHandler::OnTabletModeEnded() {
 }
 
 void HomeLauncherGestureHandler::OnImplicitAnimationsCompleted() {
-  float home_launcher_opacity = 1.f;
   const bool is_final_state_show = IsFinalStateShow();
-  NotifyHomeLauncherAnimationComplete(is_final_state_show /*shown*/,
-                                      display_.id());
+  base::ScopedClosureRunner notification_runner(base::BindOnce(
+      &HomeLauncherGestureHandler::NotifyHomeLauncherAnimationComplete,
+      base::Unretained(this), is_final_state_show, display_.id()));
+  float home_launcher_opacity = 1.f;
   if (Shell::Get()->overview_controller()->InOverviewSession()) {
     if (overview_active_on_gesture_start_ && is_final_state_show) {
       // Exit overview if event is released on the top half. This will also

ash/shelf/shelf_layout_manager.cc

@@ -112,7 +112,7 @@ bool IsTabletModeEnabled() {
 bool IsHomeScreenAvailable() {
   // Shell could be destroying. Shell destroys HomeScreenController before
   // closing all windows.
-  if (!Shell::Get()->home_screen_controller())
+  if (!Shell::Get() || !Shell::Get()->home_screen_controller())
     return false;
 
   return Shell::Get()->home_screen_controller()->IsHomeScreenAvailable();
@@ -529,15 +529,13 @@ ShelfBackgroundType ShelfLayoutManager::GetShelfBackgroundType() const {
     return SHELF_BACKGROUND_LOGIN;
   }
 
-  if (is_app_list_visible_) {
-    if (!IsHomeScreenAvailable())
-      return SHELF_BACKGROUND_APP_LIST;
-
-    // When the home screen is available, it is always visible. If the home
-    // screen is either fullscreen or being animated or dragged, show the
-    // transparent background.
+  if (IsHomeScreenAvailable()) {
+    // If the home launcher is shown, being animated, or dragged, show the
+    // default background.
     if (is_home_launcher_shown_ || is_home_launcher_target_position_shown_)
       return SHELF_BACKGROUND_DEFAULT;
+  } else if (is_app_list_visible_) {
+    return SHELF_BACKGROUND_APP_LIST;
   }
 
   const bool in_split_view_mode =

ash/shelf/shelf_layout_manager.h

@@ -418,15 +418,18 @@ class ASH_EXPORT ShelfLayoutManager : public AppListControllerObserver,
   Shelf* shelf_;
 
   // Whether the app list is visible. This is maintained by
-  // OnAppListVisibilityChanged.
+  // OnAppListVisibilityChanged. Used to determine AppList visibility in
+  // clamshell mode.
   bool is_app_list_visible_ = false;
 
   // Whether the HomeLauncher is being dragged to, or animating to fullscreen.
-  // This is maintained by OnHomeLauncherTargetPositionChanged.
+  // This is maintained by OnHomeLauncherTargetPositionChanged. Used to
+  // determine AppList visibility in tablet mode.
   bool is_home_launcher_target_position_shown_ = false;
 
   // Whether the HomeLauncher is shown. This is maintained by
-  // OnHomeLauncherAnimationComplete.
+  // OnHomeLauncherAnimationComplete. Used to determine AppList visibility in
+  // tablet mode.
   bool is_home_launcher_shown_ = false;
 
   // True to skip updating shelf visibility state.