Show overview mode button in TouchView with open modal window

ash/system/overview/overview_button_tray_unittest.cc

Index: ash/system/overview/overview_button_tray_unittest.cc
diff --git a/ash/system/overview/overview_button_tray_unittest.cc b/ash/system/overview/overview_button_tray_unittest.cc
index a7e6a3e17fe4ba9c87a6e654e576fc0b7ae8eff2..244fad29646b4eaa14e6578eeb25e241ef7a4cf2 100644
--- a/ash/system/overview/overview_button_tray_unittest.cc
+++ b/ash/system/overview/overview_button_tray_unittest.cc
@@ -182,6 +182,23 @@ TEST_F(OverviewButtonTrayTest, VisibilityChangesForLoginStatus) {
       EnableMaximizeModeWindowManager(false);
 }
 
+// Tests that the overview button becomes visible when the user enters
+// maximize mode with a system modal window open, and that it hides once
+// the user exits maximize mode.
+TEST_F(OverviewButtonTrayTest, VisibilityChangesForSystemModalWindow) {
+  scoped_ptr<aura::Window> window(
+      CreateTestModalWindowInShellWithBounds(gfx::Rect(5, 5, 20, 20)));
+  ASSERT_TRUE(Shell::GetInstance()->IsSystemModalWindowOpen());
+  Shell::GetInstance()
+      ->maximize_mode_controller()
+      ->EnableMaximizeModeWindowManager(true);
+  EXPECT_TRUE(GetTray()->visible());
+  Shell::GetInstance()
+      ->maximize_mode_controller()
+      ->EnableMaximizeModeWindowManager(false);
+  EXPECT_FALSE(GetTray()->visible());
+}
+
 // Tests that the tray only renders as active while selection is ongoing. Any
 // dismissal of overview mode clears the active state.
 TEST_F(OverviewButtonTrayTest, ActiveStateOnlyDuringOverviewMode) {