Add ability to have active window autohide shelf

ash/wm/window_util.cc

Index: ash/wm/window_util.cc
diff --git a/ash/wm/window_util.cc b/ash/wm/window_util.cc
index d4cf8abb70f74beada455cb3e62538a744c60a37..43198c86b11f3d33ba88d3178f40e84bfc3f7545 100644
--- a/ash/wm/window_util.cc
+++ b/ash/wm/window_util.cc
@@ -7,6 +7,7 @@
 #include <vector>
 
 #include "ash/common/ash_constants.h"
+#include "ash/common/shelf/wm_shelf.h"
 #include "ash/common/wm/window_state.h"
 #include "ash/common/wm/wm_event.h"
 #include "ash/common/wm/wm_screen_util.h"
@@ -83,6 +84,12 @@ void PinWindow(aura::Window* window, bool trusted) {
   wm::GetWindowState(window)->OnWMEvent(&event);
 }
 
+void SetAutoHideShelf(aura::Window* window, bool autohide) {
+  wm::GetWindowState(window)->set_hide_shelf_when_active(autohide);
+  for (WmWindow* root_window : WmShell::Get()->GetAllRootWindows())
+    WmShelf::ForWindow(root_window)->UpdateVisibilityState();
+}
+
 bool MoveWindowToDisplay(aura::Window* window, int64_t display_id) {
   DCHECK(window);
   WmWindow* root = WmShell::Get()->GetRootWindowForDisplayId(display_id);