Replace views::Event with ui::Event.

ui/views/examples/message_box_example.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/views/examples/message_box_example.h"
 
 #include "base/utf_string_conversions.h"
 #include "ui/views/controls/message_box_view.h"
 #include "ui/views/layout/grid_layout.h"
 #include "ui/views/view.h"
@@ skipping 31 matching lines @@
                         0.5f, GridLayout::USE_PREF, 0, 0);
   column_set->AddColumn(GridLayout::FILL, GridLayout::FILL,
                         0.5f, GridLayout::USE_PREF, 0, 0);
 
   layout->StartRow(0 /* no expand */, button_column);
 
   layout->AddView(status_);
   layout->AddView(toggle_);
 }
 
-void MessageBoxExample::ButtonPressed(Button* sender, const Event& event) {
+void MessageBoxExample::ButtonPressed(Button* sender, const ui::Event& event) {
   if (sender == status_) {
     message_box_view_->SetCheckBoxLabel(
         ASCIIToUTF16(BoolToOnOff(message_box_view_->IsCheckBoxSelected())));
     PrintStatus(message_box_view_->IsCheckBoxSelected() ?
        "Check Box Selected" : "Check Box Not Selected");
   } else if (sender == toggle_) {
     message_box_view_->SetCheckBoxSelected(
         !message_box_view_->IsCheckBoxSelected());
   }
 }
 
 }  // namespace examples
 }  // namespace views