ObserverList::HasObserver now takes a const pointer.

chrome/browser/extensions/api/dial/dial_service.cc

Index: chrome/browser/extensions/api/dial/dial_service.cc
diff --git a/chrome/browser/extensions/api/dial/dial_service.cc b/chrome/browser/extensions/api/dial/dial_service.cc
index 18311df9d441ecd704386b93e568ba36a7d2cc43..4197d62b9f1b3750d35516453a6162e2dda625ec 100644
--- a/chrome/browser/extensions/api/dial/dial_service.cc
+++ b/chrome/browser/extensions/api/dial/dial_service.cc
@@ -407,7 +407,7 @@ void DialServiceImpl::RemoveObserver(Observer* observer) {
   observer_list_.RemoveObserver(observer);
 }
 
-bool DialServiceImpl::HasObserver(Observer* observer) {
+bool DialServiceImpl::HasObserver(const Observer* observer) const {
   DCHECK(thread_checker_.CalledOnValidThread());
   return observer_list_.HasObserver(observer);
 }