Added a11y alert on entering overview mode

ash/wm/overview/window_selector_unittest.cc

Index: ash/wm/overview/window_selector_unittest.cc
diff --git a/ash/wm/overview/window_selector_unittest.cc b/ash/wm/overview/window_selector_unittest.cc
index 028bacd816856a72a8bc493ee611552cef90ea8f..810a908c4ff81c3561b2ce8a6fd2c1cc1f5f6e0e 100644
--- a/ash/wm/overview/window_selector_unittest.cc
+++ b/ash/wm/overview/window_selector_unittest.cc
@@ -2,6 +2,7 @@
 // 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"
@@ -252,6 +253,17 @@ class WindowSelectorTest : public test::AshTestBase {
   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));

[tdanderson, 2014/04/28 21:59:55]

Perhaps add an EXPECT_NE here to check that the alert was not sent before
ToggleOverview() was called.

[Nina, 2014/04/29 13:12:17]

Done.

+  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);