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

ash/root_window_controller.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 "ash/root_window_controller.h"
 
 #include <queue>
 #include <vector>
 
 #include "ash/ash_constants.h"
@@ skipping 27 matching lines @@
 #include "ash/wm/stacking_controller.h"
 #include "ash/wm/status_area_layout_manager.h"
 #include "ash/wm/system_background_controller.h"
 #include "ash/wm/system_modal_container_layout_manager.h"
 #include "ash/wm/toplevel_window_event_handler.h"
 #include "ash/wm/window_properties.h"
 #include "ash/wm/window_util.h"
 #include "ash/wm/workspace_controller.h"
 #include "base/command_line.h"
 #include "base/time/time.h"
+#include "ui/aura/client/activation_client.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/client/drag_drop_client.h"
 #include "ui/aura/client/tooltip_client.h"
 #include "ui/aura/root_window.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_delegate.h"
 #include "ui/aura/window_observer.h"
 #include "ui/aura/window_tracker.h"
 #include "ui/base/hit_test.h"
 #include "ui/base/models/menu_model.h"
@@ skipping 437 matching lines @@
   }
 
   Shell::GetInstance()->UpdateShelfVisibility();
 }
 
 void RootWindowController::UpdateShelfVisibility() {
   shelf_->shelf_layout_manager()->UpdateVisibilityState();
 }
 
 const aura::Window* RootWindowController::GetFullscreenWindow() const {
+  aura::Window* active_window =
+      aura::client::GetActivationClient(root_window_.get())->GetActiveWindow();
+  if (active_window && wm::IsWindowFullscreen(active_window))
+    return active_window;
+
   const aura::Window* container = GetContainer(kShellWindowId_DefaultContainer);
   for (size_t i = 0; i < container->children().size(); ++i) {
     aura::Window* child = container->children()[i];
     if (wm::IsWindowFullscreen(child))
       return child;

[oshima, 2013/09/04 23:45:55]

Given that multiple fullscreen / immersive windows co-exist in one root window,
and non fullscreen window can overlap on top of it, I think you need to get top
most fullscreen wnidow.

Would you also mind renaming this GetTopmostFullscreenWindow ?

[Jun Mukai, 2013/09/05 00:04:09]

Done.

   }
   return NULL;
 }
 
 void RootWindowController::InitKeyboard() {
   if (keyboard::IsKeyboardEnabled()) {
     aura::Window* parent = root_window();
 
     keyboard::KeyboardControllerProxy* proxy =
         Shell::GetInstance()->delegate()->CreateKeyboardControllerProxy();
@@ skipping 288 matching lines @@
 
 void RootWindowController::OnTouchHudProjectionToggled(bool enabled) {
   if (enabled)
     EnableTouchHudProjection();
   else
     DisableTouchHudProjection();
 }
 
 }  // namespace internal
 }  // namespace ash