Makes CaptureController be created and owned by WMState

ui/wm/core/wm_state.h

Index: ui/wm/core/wm_state.h
diff --git a/ui/wm/core/wm_state.h b/ui/wm/core/wm_state.h
index f82632c0ab4b632349e372c5c74f7ed4ad08f6f5..660a1c8450805d8705a161cb2127db365c045bbc 100644
--- a/ui/wm/core/wm_state.h
+++ b/ui/wm/core/wm_state.h
@@ -12,6 +12,7 @@
 
 namespace wm {
 
+class CaptureController;
 class TransientWindowController;
 class TransientWindowStackingClient;
 
@@ -24,6 +25,7 @@ class WM_EXPORT WMState {
  private:
   std::unique_ptr<TransientWindowStackingClient> window_stacking_client_;
   std::unique_ptr<TransientWindowController> transient_window_client_;
+  std::unique_ptr<CaptureController> capture_controller_;
 
   DISALLOW_COPY_AND_ASSIGN(WMState);
 };