ObserverList::HasObserver now takes a const pointer.

ui/views/widget/widget.cc

Index: ui/views/widget/widget.cc
diff --git a/ui/views/widget/widget.cc b/ui/views/widget/widget.cc
index eecbc23cec0d008b133a38cf6721adea37fa2716..7f649c04025bffe95c5f1ab444279baf94f77572 100644
--- a/ui/views/widget/widget.cc
+++ b/ui/views/widget/widget.cc
@@ -393,7 +393,7 @@ void Widget::RemoveObserver(WidgetObserver* observer) {
   observers_.RemoveObserver(observer);
 }
 
-bool Widget::HasObserver(WidgetObserver* observer) {
+bool Widget::HasObserver(const WidgetObserver* observer) const {
   return observers_.HasObserver(observer);
 }
 
@@ -405,7 +405,7 @@ void Widget::RemoveRemovalsObserver(WidgetRemovalsObserver* observer) {
   removals_observers_.RemoveObserver(observer);
 }
 
-bool Widget::HasRemovalsObserver(WidgetRemovalsObserver* observer) {
+bool Widget::HasRemovalsObserver(const WidgetRemovalsObserver* observer) const {
   return removals_observers_.HasObserver(observer);
 }