Prevent a user from hiding the shelf via a gesture when there are no visible windows

ash/shelf/shelf_layout_manager_unittest.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/shelf/shelf_layout_manager.h"
 
 #include "ash/accelerators/accelerator_controller.h"
 #include "ash/accelerators/accelerator_table.h"
 #include "ash/ash_switches.h"
 #include "ash/display/display_controller.h"
@@ skipping 558 matching lines @@
       base::Bind(&ShelfDragCallback::ProcessScroll,
                  base::Unretained(&handler)));
   EXPECT_EQ(SHELF_HIDDEN, shelf->visibility_state());
   EXPECT_EQ(SHELF_AUTO_HIDE_BEHAVIOR_ALWAYS, shelf->auto_hide_behavior());
   EXPECT_EQ(bounds_fullscreen.ToString(), window->bounds().ToString());
 
   // Close actually, otherwise further event may be affected since widget
   // is fullscreen status.
   widget->Close();
   RunAllPendingInMessageLoop();
+
+  // The shelf should be shown because there are no more visible windows.
+  EXPECT_EQ(SHELF_AUTO_HIDE, shelf->visibility_state());
+  EXPECT_EQ(SHELF_AUTO_HIDE_SHOWN, shelf->auto_hide_state());
+  EXPECT_EQ(SHELF_AUTO_HIDE_BEHAVIOR_ALWAYS, shelf->auto_hide_behavior());
+
+  // Swipe-up to hide. This should have no effect because there are no visible
+  // windows.
+  end = below_start - delta;
+  generator.GestureScrollSequenceWithCallback(below_start, end,
+      base::TimeDelta::FromMilliseconds(10), kNumScrollSteps,
+      base::Bind(&ShelfDragCallback::ProcessScroll,
+                 base::Unretained(&handler)));
+  EXPECT_EQ(SHELF_AUTO_HIDE, shelf->visibility_state());
+  EXPECT_EQ(SHELF_AUTO_HIDE_SHOWN, shelf->auto_hide_state());
+  EXPECT_EQ(SHELF_AUTO_HIDE_BEHAVIOR_ALWAYS, shelf->auto_hide_behavior());
 }
 
 // Fails on Mac only.  Need to be implemented.  http://crbug.com/111279.
 #if defined(OS_MACOSX) || defined(OS_WIN)
 #define MAYBE_SetVisible DISABLED_SetVisible
 #else
 #define MAYBE_SetVisible SetVisible
 #endif
 // Makes sure SetVisible updates work area and widget appropriately.
 TEST_F(ShelfLayoutManagerTest, MAYBE_SetVisible) {
@@ skipping 1089 matching lines @@
   scoped_ptr<aura::Window> w1(CreateTestWindow());
   w1->Show();
   wm::ActivateWindow(w1.get());
   EXPECT_EQ(SHELF_BACKGROUND_OVERLAP, GetShelfWidget()->GetBackgroundType());
   w1->SetProperty(aura::client::kShowStateKey, ui::SHOW_STATE_MAXIMIZED);
   EXPECT_EQ(SHELF_BACKGROUND_OVERLAP, GetShelfWidget()->GetBackgroundType());
 }
 
 }  // namespace internal
 }  // namespace ash