Moves couple of WmShell methods to standalone functions

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 6741eb71efd85ecc2464106c5ee5fad32b69ff23..645cadffc92f62a56e29a20ecd6654e345c82e80 100644
--- a/ash/wm/window_util.cc
+++ b/ash/wm/window_util.cc
@@ -18,6 +18,8 @@
 #include "ash/wm/window_properties.h"
 #include "ash/wm/window_state_aura.h"
 #include "ui/aura/client/aura_constants.h"
+#include "ui/aura/client/capture_client.h"
+#include "ui/aura/client/focus_client.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_delegate.h"
 #include "ui/aura/window_event_dispatcher.h"
@@ -75,6 +77,15 @@ bool CanActivateWindow(aura::Window* window) {
   return ::wm::CanActivateWindow(window);
 }
 
+aura::Window* GetFocusedWindow() {
+  return aura::client::GetFocusClient(Shell::GetPrimaryRootWindow())
+      ->GetFocusedWindow();
+}
+
+aura::Window* GetCaptureWindow() {
+  return aura::client::GetCaptureWindow(Shell::GetPrimaryRootWindow());
+}
+
 bool IsWindowUserPositionable(aura::Window* window) {
   return GetWindowState(window)->IsUserPositionable();
 }