arc: Fix crash on deferred app launch.

chrome/browser/ui/ash/launcher/app_shortcut_launcher_item_controller.cc

Index: chrome/browser/ui/ash/launcher/app_shortcut_launcher_item_controller.cc
diff --git a/chrome/browser/ui/ash/launcher/app_shortcut_launcher_item_controller.cc b/chrome/browser/ui/ash/launcher/app_shortcut_launcher_item_controller.cc
index 1bff289c70aefa1ef259da4d1eac6242342c18ae..1212d2bd6baf98a513e1f7ba883c6a735c6b9ed9 100644
--- a/chrome/browser/ui/ash/launcher/app_shortcut_launcher_item_controller.cc
+++ b/chrome/browser/ui/ash/launcher/app_shortcut_launcher_item_controller.cc
@@ -188,6 +188,10 @@ void AppShortcutLauncherItemController::Close() {
   }
 }
 
+bool AppShortcutLauncherItemController::IsShortcut() const {
+  return true;

[msw, 2017/03/14 01:24:59]

What does it mean if LauncherItemController::IsShortcut() != (ShelfItem::type ==
TYPE_APP_SHORTCUT)? Instead, could this launcher item controller subclass ensure
that the associated shelf item has type ash::TYPE_APP_SHORTCUT (perhaps by
setting the item type to that value in the ctor)? Or is the issue that
non-"IsShortcut" items were marked as TYPE_APP_SHORTCUT? Either way, we should
avoid ShelfItemDelegate/LauncherItemController expansion going forward.

[khmel, 2017/03/14 15:25:44]

Hi,
I don't clear understand your idea. The reason of this crash is impossibility to
determine if shelf item represents running app or just a shortcut. With recent
refactoring ash::TYPE_APP_SHORTCUT represents and shortcut and running app. When
app is not running it has type ash::TYPE_APP_SHORTCUT. When app is running its
shelf item still has type ash::TYPE_APP_SHORTCUT. Before in this scenario it was
changed from ash::TYPE_APP_SHORTCUT to ash::TYPE_APP. Do you suggest to restore
functionality by passing type to base class as it was here:
https://codereview.chromium.org/2545923004/diff/80001/chrome/browser/ui/ash/l...
?

[msw, 2017/03/14 17:19:32]

My idea is to update and check ShelfItem struct values, instead of calling
controller instance functions. So, something should be updating the ShelfItem's
|type| and/or |status| when the item changes from a shortcut to a running app.
There are two possibilities:
1) Running apps should have ShelfItem::type == ash::TYPE_APP, but shortcuts
(pinned items that are not running) should have ShelfItem::type ==
ash::TYPE_APP_SHORTCUT. See ShelfItem::type here:
https://cs.chromium.org/chromium/src/ash/common/shelf/shelf_item_types.h?l=25
2) Even better, we disregard ShelfItem::type (both should eventually just be
app...) and we check the ShelfItem::status value (either STATUS_CLOSED or not).
See ShelfItem::status here:
https://cs.chromium.org/chromium/src/ash/common/shelf/shelf_item_types.h?l=34
I hope that's clearer. What do you think?

[khmel, 2017/03/14 20:19:56]

Done as per offline discussion.

+}
+
 std::vector<content::WebContents*>
 AppShortcutLauncherItemController::GetRunningApplications() {
   std::vector<content::WebContents*> items;