Add a lock screen example.

ui/aura/window.cc

 // Copyright (c) 2011 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/aura/window.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "ui/aura/desktop.h"
 #include "ui/aura/event.h"
 #include "ui/aura/event_filter.h"
 #include "ui/aura/focus_manager.h"
 #include "ui/aura/layout_manager.h"
 #include "ui/aura/window_delegate.h"
 #include "ui/base/animation/multi_animation.h"
 #include "ui/gfx/canvas_skia.h"
 #include "ui/gfx/compositor/compositor.h"
 #include "ui/gfx/compositor/layer.h"
 
 namespace aura {
 
 using internal::RootWindow;
 
 Window::Window(WindowDelegate* delegate)
     : delegate_(delegate),
       visible_(false),
       parent_(NULL),
       id_(-1),
-      user_data_(NULL) {
+      user_data_(NULL),
+      consumes_events_(false) {
 }
 
 Window::~Window() {
   // Let the delegate know we're in the processing of destroying.
   if (delegate_)
     delegate_->OnWindowDestroying();
 
   // Let the root know so that it can remove any references to us.
   RootWindow* root = GetRoot();
   if (root)
@@ skipping 166 matching lines @@
     Window* child = *i;
     if (!child->visible())
       continue;
     gfx::Point point_in_child_coords(point);
     Window::ConvertPointToWindow(this, child, &point_in_child_coords);
     if (child->HitTest(point_in_child_coords)) {
       Window* handler = child->GetEventHandlerForPoint(point_in_child_coords);
       if (handler && handler->delegate())
         return handler;
     }
+    if (child->consumes_events_ && !child->children().empty())
+      return NULL;
   }
   return delegate_ ? this : NULL;
 }
 
 internal::FocusManager* Window::GetFocusManager() {
   return parent_ ? parent_->GetFocusManager() : NULL;
 }
 
 void Window::SetCapture() {
   if (!visible_)
@@ skipping 43 matching lines @@
 
 void Window::SchedulePaint() {
   SchedulePaintInRect(gfx::Rect(0, 0, bounds().width(), bounds().height()));
 }
 
 void Window::OnPaintLayer(gfx::Canvas* canvas) {
   delegate_->OnPaint(canvas);
 }
 
 }  // namespace aura