Replace views::Event with ui::Event.

ash/system/web_notification/web_notification_tray.cc

Index: ash/system/web_notification/web_notification_tray.cc
===================================================================
--- ash/system/web_notification/web_notification_tray.cc	(revision 151055)
+++ ash/system/web_notification/web_notification_tray.cc	(working copy)
@@ -445,7 +445,7 @@
 
   // Overridden from ButtonListener.
   virtual void ButtonPressed(views::Button* sender,
-                             const views::Event& event) OVERRIDE {
+                             const ui::Event& event) OVERRIDE {
     if (sender == close_button_)
       tray_->SendRemoveNotification(notification_.id);
   }
@@ -519,7 +519,7 @@
 
   // Overridden from ButtonListener.
   virtual void ButtonPressed(views::Button* sender,
-                             const views::Event& event) OVERRIDE {
+                             const ui::Event& event) OVERRIDE {
     if (sender == close_all_button_)
       tray_->SendRemoveAllNotifications();
   }
@@ -1007,7 +1007,7 @@
     delegate_->DisableNotificationsFromSource(id);
 }
 
-bool WebNotificationTray::PerformAction(const views::Event& event) {
+bool WebNotificationTray::PerformAction(const ui::Event& event) {
   if (message_center_bubble())
     HideMessageCenterBubble();
   else