Update 3 ObserverLists introduced after r584330 to be ::Unchecked.

r584330 updated all annotations on ObserverList declarations to be
::Unchecked, but a few new declarations appeared since that. They
need to be ::Unchecked as well in order for https://crrev.com/c/1053338
to land cleanly.

TBR=gab@chromium.org

Bug: 842987
Cq-Include-Trybots: luci.chromium.try:linux_mojo
Change-Id: I1c6d7ae8e9668438afa8184fd0c3884a21e9732d
Reviewed-on: https://chromium-review.googlesource.com/1182712
Commit-Queue: Trent Apted <tapted@chromium.org>
Reviewed-by: Trent Apted <tapted@chromium.org>
Cr-Commit-Position: refs/heads/master@{#584682}

ash/assistant/model/assistant_cache_model.h

@@ -44,7 +44,7 @@ class AssistantCacheModel {
 
   std::vector<AssistantSuggestionPtr> conversation_starters_;
 
-  base::ObserverList<AssistantCacheModelObserver> observers_;
+  base::ObserverList<AssistantCacheModelObserver>::Unchecked observers_;
 
   DISALLOW_COPY_AND_ASSIGN(AssistantCacheModel);
 };

chrome/browser/ui/toolbar/media_router_action_controller.h

@@ -133,7 +133,7 @@ class MediaRouterActionController : public media_router::IssuesObserver,
 
   PrefChangeRegistrar pref_change_registrar_;
 
-  base::ObserverList<Observer> observers_;
+  base::ObserverList<Observer>::Unchecked observers_;
 
   base::WeakPtrFactory<MediaRouterActionController> weak_factory_;
 

services/network/crl_set_distributor.h

@@ -53,8 +53,9 @@ class COMPONENT_EXPORT(NETWORK_SERVICE) CRLSetDistributor {
  private:
   void OnCRLSetParsed(scoped_refptr<net::CRLSet> crl_set);
 
-  base::ObserverList<Observer, true /*check_empty*/, false /*allow_reentrancy*/>
-      observers_;
+  base::ObserverList<Observer,
+                     true /*check_empty*/,
+                     false /*allow_reentrancy*/>::Unchecked observers_;
   scoped_refptr<net::CRLSet> crl_set_;
 
   base::WeakPtrFactory<CRLSetDistributor> weak_factory_;