Moves WindowSelectorController onto WmShell

ash/common/wm_shell.cc

Index: ash/common/wm_shell.cc
diff --git a/ash/common/wm_shell.cc b/ash/common/wm_shell.cc
index f0d1b68753d7d4523424468dbfa927277f6bdd99..f74477e63af4556f8993982b477cec17c857f9de 100644
--- a/ash/common/wm_shell.cc
+++ b/ash/common/wm_shell.cc
@@ -8,6 +8,7 @@
 #include "ash/common/shell_window_ids.h"
 #include "ash/common/system/tray/system_tray_delegate.h"
 #include "ash/common/system/tray/wm_system_tray_notifier.h"
+#include "ash/common/wm/overview/window_selector_controller.h"
 #include "ash/common/wm_window.h"
 #include "base/logging.h"
 
@@ -66,4 +67,12 @@ void WmShell::SetSystemTrayDelegate(
   }
 }
 
+void WmShell::CreateWindowSelectorController() {
+  window_selector_controller_.reset(new WindowSelectorController());

[James Cook, 2016/06/22 22:46:19]

WindowSelectorController does nothing in its constructor and destructor. Do you
think it could be initialized in the WmShell constructor, similar to
FocusCycler?

This would eliminate the need for null checks with window_selector_controller().

[sky, 2016/06/22 23:19:39]

I made construction immediate, but destruction has to be explicit. While it
looks like ~WSC does nothing, it deletes the WindowSelector, which deletes a
bunch of other stuff. The deletion has to happen where it is or we have shutdown
problems.
I suspect these were never really needed.

+}
+
+void WmShell::DeleteWindowSelectorController() {
+  window_selector_controller_.reset();
+}
+
 }  // namespace ash