Fix the ~AppWindowLauncherItemController crash issue.

In ~AppWindowLauncherItemController, AppWindowBase::SetController could
remove the window from windows_, so the for loop for windows_ might
cause crash.

Modify the for loop to use the reverse iterator to resolve the crash
issue.

BUG=1164188

Change-Id: Ifa561df71d3be1daf0c3505e8836d1cb60fa9143
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2633483Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Nancy Wang <nancylingwang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#844880}

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

@@ -64,9 +64,11 @@ AppWindowLauncherItemController::AppWindowLauncherItemController(
     : ash::ShelfItemDelegate(shelf_id) {}
 
 AppWindowLauncherItemController::~AppWindowLauncherItemController() {
-  for (auto* window : windows_)
-    window->SetController(nullptr);
+  WindowList windows(windows_);
   for (auto* window : hidden_windows_)
+    windows.push_back(window);
+
+  for (auto* window : windows)
     window->SetController(nullptr);
 }