Replace more ObserverList with base::ObserverList.

components/view_manager/server_view.cc

Index: components/view_manager/server_view.cc
diff --git a/components/view_manager/server_view.cc b/components/view_manager/server_view.cc
index 344d2a878e0bbc09c46ac2c29783e1fc451e012a..d916afa422bef931571703b74814afe32f1c8d2c 100644
--- a/components/view_manager/server_view.cc
+++ b/components/view_manager/server_view.cc
@@ -21,7 +21,7 @@ ServerView::ServerView(ServerViewDelegate* delegate, const ViewId& id)
       // Don't notify newly added observers during notification. This causes
       // problems for code that adds an observer as part of an observer
       // notification (such as ServerViewDrawTracker).
-      observers_(ObserverList<ServerViewObserver>::NOTIFY_EXISTING_ONLY) {
+      observers_(base::ObserverList<ServerViewObserver>::NOTIFY_EXISTING_ONLY) {
   DCHECK(delegate);  // Must provide a delegate.
 }