Moves couple of WmShell methods to standalone functions

ash/virtual_keyboard_controller.cc

Index: ash/virtual_keyboard_controller.cc
diff --git a/ash/virtual_keyboard_controller.cc b/ash/virtual_keyboard_controller.cc
index ca7d78cee32b8e3d4c8999ac0d6082626f323bbe..c0ec291e544443cba7c9cca372a70945143c47dc 100644
--- a/ash/virtual_keyboard_controller.cc
+++ b/ash/virtual_keyboard_controller.cc
@@ -13,6 +13,7 @@
 #include "ash/common/wm_window.h"
 #include "ash/root_window_controller.h"
 #include "ash/shell.h"
+#include "ash/wm/window_util.h"
 #include "base/command_line.h"
 #include "base/strings/string_util.h"
 #include "ui/display/display.h"
@@ -139,11 +140,11 @@ void VirtualKeyboardController::MoveKeyboardToTouchableDisplay() {
   const display::Display current_display =
       screen->GetDisplayNearestWindow(container);
 
-  if (WmShell::Get()->GetFocusedWindow() != nullptr) {
+  if (wm::GetFocusedWindow() != nullptr) {
     // Move the virtual keyboard to the focused display if that display has
     // touch capability or keyboard is locked
     const display::Display focused_display =
-        WmShell::Get()->GetFocusedWindow()->GetDisplayNearestWindow();
+        WmWindow::Get(wm::GetFocusedWindow())->GetDisplayNearestWindow();
     if (current_display.id() != focused_display.id() &&
         focused_display.id() != display::kInvalidDisplayId &&
         focused_display.touch_support() ==