Pressing tab in overview should cycle windows.

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 <algorithm>
 
 #include "ash/accessibility_delegate.h"
 #include "ash/drag_drop/drag_drop_controller.h"
 #include "ash/root_window_controller.h"
 #include "ash/screen_util.h"
@@ skipping 847 matching lines @@
   // bounds.
   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))));
   }
 }
 
+// Tests traversing some windows in overview mode with the tab key.
+TEST_F(WindowSelectorTest, BasicTabKeyNavigation) {
+  gfx::Rect bounds(0, 0, 100, 100);
+  scoped_ptr<aura::Window> window2(CreateWindow(bounds));
+  scoped_ptr<aura::Window> window1(CreateWindow(bounds));
+  ToggleOverview();
+
+  SendKey(ui::VKEY_TAB);
+  EXPECT_EQ(GetSelectedWindow(), window1.get());
+  SendKey(ui::VKEY_TAB);
+  EXPECT_EQ(GetSelectedWindow(), window2.get());
+  SendKey(ui::VKEY_TAB);
+  EXPECT_EQ(GetSelectedWindow(), window1.get());
+}
+
 // Tests traversing some windows in overview mode with the arrow keys in every
 // possible direction.
 TEST_F(WindowSelectorTest, BasicArrowKeyNavigation) {
   if (!SupportsHostWindowResize())
     return;
   const size_t test_windows = 7;
   UpdateDisplay("400x300");
   ScopedVector<aura::Window> windows;
   for (size_t i = test_windows; i > 0; i--)
     windows.push_back(CreateWindowWithId(gfx::Rect(0, 0, 100, 100), i));
@@ skipping 237 matching lines @@
    // Dimming all the items should hide the selection widget.
    FilterItems("Pop");
    EXPECT_FALSE(selection_widget_active());
 
    // Undimming one window should automatically select it.
    FilterItems("Rock and roll");
    EXPECT_EQ(GetSelectedWindow(), window2.get());
 }
 
 }  // namespace ash