Added a11y alert on entering overview mode

ash/wm/overview/window_selector_unittest.cc

 // Copyright 2013 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/accessibility_delegate.h"
 #include "ash/drag_drop/drag_drop_controller.h"
 #include "ash/root_window_controller.h"
 #include "ash/screen_util.h"
 #include "ash/shelf/shelf.h"
 #include "ash/shelf/shelf_widget.h"
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
 #include "ash/test/ash_test_base.h"
 #include "ash/test/shelf_test_api.h"
 #include "ash/test/shelf_view_test_api.h"
@@ skipping 230 matching lines @@
   }
 
  private:
   aura::test::TestWindowDelegate delegate_;
   NonActivatableActivationDelegate non_activatable_activation_delegate_;
   scoped_ptr<test::ShelfViewTestAPI> shelf_view_test_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowSelectorTest);
 };
 
+// Tests that an a11y alert is sent on entering overview mode.
+TEST_F(WindowSelectorTest, A11yAlertOnOverviewMode) {
+  gfx::Rect bounds(0, 0, 400, 400);
+  AccessibilityDelegate* delegate =
+      ash::Shell::GetInstance()->accessibility_delegate();
+  scoped_ptr<aura::Window> window1(CreateWindow(bounds));
+  EXPECT_NE(delegate->GetLastAccessibilityAlert(),
+            A11Y_ALERT_WINDOW_OVERVIEW_MODE_ENTERED);
+  ToggleOverview();
+  EXPECT_EQ(delegate->GetLastAccessibilityAlert(),
+            A11Y_ALERT_WINDOW_OVERVIEW_MODE_ENTERED);
+}
+
 // Tests entering overview mode with two windows and selecting one.
 TEST_F(WindowSelectorTest, Basic) {
   gfx::Rect bounds(0, 0, 400, 400);
   aura::Window* root_window = Shell::GetPrimaryRootWindow();
   scoped_ptr<aura::Window> window1(CreateWindow(bounds));
   scoped_ptr<aura::Window> window2(CreateWindow(bounds));
   scoped_ptr<aura::Window> panel1(CreatePanelWindow(bounds));
   scoped_ptr<aura::Window> panel2(CreatePanelWindow(bounds));
   EXPECT_TRUE(WindowsOverlapping(window1.get(), window2.get()));
   EXPECT_TRUE(WindowsOverlapping(panel1.get(), panel2.get()));
@@ skipping 906 matching lines @@
   UpdateDisplay("600x200/r");
   EXPECT_EQ("0,0 200x600", root_window->bounds().ToString());
   for (ScopedVector<aura::Window>::iterator iter = windows.begin();
        iter != windows.end(); ++iter) {
     EXPECT_TRUE(root_window->bounds().Contains(
         ToEnclosingRect(GetTransformedTargetBounds(*iter))));
   }
 }
 
 }  // namespace ash