Always retry GuestOsRegistryService icon fetches

Some VMs such as PluginVM do not always send an AppListUpdate
when they start, so it is better to always query when an icon is fetched
and we don't have it.

Bug: b/166150220
Change-Id: I5979d4f36986b46e86d846ff40fc61a5101d1bbd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2377170Reviewed-by: Timothy Loh <timloh@chromium.org>
Commit-Queue: Joel Hockey <joelhockey@chromium.org>
Cr-Commit-Position: refs/heads/master@{#801681}

chrome/browser/chromeos/guest_os/guest_os_registry_service.cc

@@ -679,16 +679,6 @@ void GuestOsRegistryService::RequestIcon(
     std::move(callback).Run({});
     return;
   }
-  // First check to see if this request is in the retry list. If so return
-  // immediately with an empty icon.
-  const auto retry_iter = retry_icon_requests_.find(app_id);
-  if (retry_iter != retry_icon_requests_.end()) {
-    if (retry_iter->second & (1 << scale_factor)) {
-      // Icon request already setup to be retried when we are active.
-      std::move(callback).Run({});
-      return;
-    }
-  }
 
   // Coalesce calls to the container.
   auto& callbacks = active_icon_requests_[{app_id, scale_factor}];