Keep dedicated layers for hiding animation

ash/wm/workspace_controller_unittest.cc

Index: ash/wm/workspace_controller_unittest.cc
diff --git a/ash/wm/workspace_controller_unittest.cc b/ash/wm/workspace_controller_unittest.cc
index 0438c83f421998f82978ddc3e44784a94dfb0b99..106ba52e7dbd07398ac99ade1aa45299b2b0a11a 100644
--- a/ash/wm/workspace_controller_unittest.cc
+++ b/ash/wm/workspace_controller_unittest.cc
@@ -353,11 +353,16 @@ TEST_F(WorkspaceControllerTest, MinimizeFullscreenWindow) {
   EXPECT_FALSE(w2_state->IsActive());
   EXPECT_FALSE(w2->layer()->IsDrawn());
   EXPECT_TRUE(w1_state->IsActive());
+  EXPECT_EQ(w2.get(), GetDesktop()->children()[0]);
+  EXPECT_EQ(w1.get(), GetDesktop()->children()[1]);
 
   // Make the window normal.
   w2->SetProperty(aura::client::kShowStateKey, ui::SHOW_STATE_NORMAL);
-  EXPECT_EQ(w1.get(), GetDesktop()->children()[0]);
-  EXPECT_EQ(w2.get(), GetDesktop()->children()[1]);
+  // Setting back to normal doesn't change the activation.
+  EXPECT_FALSE(w2_state->IsActive());
+  EXPECT_TRUE(w1_state->IsActive());
+  EXPECT_EQ(w2.get(), GetDesktop()->children()[0]);
+  EXPECT_EQ(w1.get(), GetDesktop()->children()[1]);
   EXPECT_TRUE(w2->layer()->IsDrawn());
 }