base: Do not allow MessagePumpObservers to consume events.

chrome/browser/ui/views/notifications/balloon_collection_views.cc

Index: chrome/browser/ui/views/notifications/balloon_collection_views.cc
diff --git a/chrome/browser/ui/views/notifications/balloon_collection_views.cc b/chrome/browser/ui/views/notifications/balloon_collection_views.cc
index 8da6940b277f105270ee98ca18579e610ab1654f..9f39666623da63b5fde3f9997b14fc8f3dd01720 100644
--- a/chrome/browser/ui/views/notifications/balloon_collection_views.cc
+++ b/chrome/browser/ui/views/notifications/balloon_collection_views.cc
@@ -44,10 +44,7 @@ void BalloonCollectionImpl::PositionBalloons(bool reposition) {
   PositionBalloonsInternal(reposition);
 }
 
-base::EventStatus BalloonCollectionImpl::WillProcessEvent(
-    const base::NativeEvent& event) {
-  return base::EVENT_CONTINUE;
-}
+void BalloonCollectionImpl::WillProcessEvent(const base::NativeEvent& event) {}
 
 void BalloonCollectionImpl::DidProcessEvent(const base::NativeEvent& event) {
 #if defined(OS_WIN)