Fix pressing enter key crashes overview mode without a selection.

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 01fad7d9c29807220146439f26ce8a2b4e914de5..8b223968d54626f647cb71d857126d5217ca9973 100644
--- a/ash/wm/overview/window_selector_unittest.cc
+++ b/ash/wm/overview/window_selector_unittest.cc
@@ -861,4 +861,29 @@ TEST_F(WindowSelectorTest, BasicMultiMonitorArrowKeyNavigation) {
   EXPECT_EQ(GetSelectedWindow(), window4.get());
 }
 
+// Tests selecting a window in overview mode with the return key.
+TEST_F(WindowSelectorTest, SelectWindowWithReturnKey) {
+  gfx::Rect bounds1(0, 0, 100, 100);

[tdanderson, 2014/06/06 21:15:18]

nit: bounds, not bounds1.

[Nina, 2014/06/06 21:44:32]

Done.

+  scoped_ptr<aura::Window> window2(CreateWindow(bounds1));

[tdanderson, 2014/06/06 21:15:18]

nit: declare window1 before window2

[Nina, 2014/06/06 21:44:32]

The reason the declaration is in that order is so that, in overview mode, they
are ordered:
+-------+ +-------+
|window1| |window2|
+-------+ +-------+

+  scoped_ptr<aura::Window> window1(CreateWindow(bounds1));
+  ToggleOverview();
+
+  // Pressing the return key without a selection widget should not do anything.
+  SendKey(ui::VKEY_RETURN);
+  EXPECT_TRUE(IsSelecting());
+
+  // Select the first window.
+  SendKey(ui::VKEY_RIGHT);
+  SendKey(ui::VKEY_RETURN);
+  ASSERT_FALSE(IsSelecting());

[tdanderson, 2014/06/06 21:15:17]

EXPECT_FALSE? (ASSERT_FALSE will crash the test at this point if it fails. Is
that intentional?)

[Nina, 2014/06/06 21:44:32]

I want the test to stop if that fails as the outcome of the following 
assertions would be pointless.

+  EXPECT_TRUE(wm::IsActiveWindow(window1.get()));
+
+  // Select the second window.
+  ToggleOverview();
+  SendKey(ui::VKEY_RIGHT);
+  SendKey(ui::VKEY_RIGHT);
+  SendKey(ui::VKEY_RETURN);
+  EXPECT_TRUE(wm::IsActiveWindow(window2.get()));

[tdanderson, 2014/06/06 21:15:17]

Can you also add an EXPECT for IsSelecting() here too?

[Nina, 2014/06/06 21:44:32]

Sure.

+}
+
 }  // namespace ash