RootWindowController::GetFullscreenWindow() should return the active one.

ash/root_window_controller.cc

Index: ash/root_window_controller.cc
diff --git a/ash/root_window_controller.cc b/ash/root_window_controller.cc
index 9854d36a909a684c052bf5dcf9fd415781b5e1ad..5f934354eb1e6d7edf45150074e0b29795c122ce 100644
--- a/ash/root_window_controller.cc
+++ b/ash/root_window_controller.cc
@@ -501,9 +501,9 @@ void RootWindowController::UpdateShelfVisibility() {
   shelf_->shelf_layout_manager()->UpdateVisibilityState();
 }
 
-const aura::Window* RootWindowController::GetFullscreenWindow() const {
+const aura::Window* RootWindowController::GetTopmostFullscreenWindow() const {
   const aura::Window* container = GetContainer(kShellWindowId_DefaultContainer);
-  for (size_t i = 0; i < container->children().size(); ++i) {
+  for (int i = container->children().size() - 1; i >= 0; --i) {

[sky, 2013/09/05 16:21:59]

How about a reverse iterator so I don't have to worry about overflow?

[Jun Mukai, 2013/09/05 18:30:53]

Done.

     aura::Window* child = container->children()[i];
     if (wm::IsWindowFullscreen(child))
       return child;