aura: Some changes in Window and Desktop.

ui/aura/window.cc

Index: ui/aura/window.cc
diff --git a/ui/aura/window.cc b/ui/aura/window.cc
index 07c48e64fc089fbc2a43102b87cbb791ca4dba68..20819d89a93369da8c59e42f19099283f40eb631 100644
--- a/ui/aura/window.cc
+++ b/ui/aura/window.cc
@@ -13,6 +13,7 @@
 #include "ui/aura/event_filter.h"
 #include "ui/aura/layout_manager.h"
 #include "ui/aura/window_delegate.h"
+#include "ui/aura/window_observer.h"
 #include "ui/aura/window_types.h"
 #include "ui/base/animation/multi_animation.h"
 #include "ui/gfx/canvas_skia.h"
@@ -35,6 +36,8 @@ Window::Window(WindowDelegate* delegate)
 }
 
 Window::~Window() {
+  FOR_EACH_OBSERVER(WindowObserver, observers_, OnWindowClosing(this));
+
   // Let the delegate know we're in the processing of destroying.
   if (delegate_)
     delegate_->OnWindowDestroying();
@@ -259,6 +262,14 @@ bool Window::OnKeyEvent(KeyEvent* event) {
   return IsVisible() && delegate_->OnKeyEvent(event);
 }
 
+void Window::AddObserver(WindowObserver* observer) {
+  observers_.AddObserver(observer);
+}
+
+void Window::RemoveObserver(WindowObserver* observer) {
+  observers_.RemoveObserver(observer);
+}
+
 bool Window::HitTest(const gfx::Point& point) {
   gfx::Rect local_bounds(gfx::Point(), bounds().size());
   // TODO(beng): hittest masks.
@@ -371,6 +382,9 @@ void Window::SetVisible(bool visible) {
     if (delegate_)
       delegate_->OnWindowVisibilityChanged(is_visible);
   }
+
+  FOR_EACH_OBSERVER(WindowObserver, observers_,
+                    OnWindowVisibilityChanged(this));
 }
 
 void Window::SchedulePaint() {