chromeos: convert more ash/wm code to aura::Window

ash/wm/panels/panel_window_event_handler.cc

Index: ash/wm/panels/panel_window_event_handler.cc
diff --git a/ash/wm/panels/panel_window_event_handler.cc b/ash/wm/panels/panel_window_event_handler.cc
index 2a222ef0c3e20be5894059f9dec323cde47d110d..4de0b0cc6ae616530f0c9cb8535631926b76e53a 100644
--- a/ash/wm/panels/panel_window_event_handler.cc
+++ b/ash/wm/panels/panel_window_event_handler.cc
@@ -6,6 +6,7 @@
 
 #include "ash/shell_port.h"
 #include "ash/wm/window_state.h"
+#include "ash/wm/window_util.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_delegate.h"
 #include "ui/base/hit_test.h"
@@ -22,8 +23,7 @@ void PanelWindowEventHandler::OnMouseEvent(ui::MouseEvent* event) {
   if (!event->handled() && event->type() == ui::ET_MOUSE_PRESSED &&
       event->flags() & ui::EF_IS_DOUBLE_CLICK &&
       event->IsOnlyLeftMouseButton() &&
-      target->delegate()->GetNonClientComponent(event->location()) ==
-          HTCAPTION) {
+      wm::GetNonClientComponent(target, event->location()) == HTCAPTION) {
     ShellPort::Get()->RecordUserMetricsAction(UMA_PANEL_MINIMIZE_CAPTION_CLICK);
     wm::GetWindowState(target)->Minimize();
     event->StopPropagation();
@@ -35,8 +35,7 @@ void PanelWindowEventHandler::OnGestureEvent(ui::GestureEvent* event) {
   aura::Window* target = static_cast<aura::Window*>(event->target());
   if (!event->handled() && event->type() == ui::ET_GESTURE_TAP &&
       event->details().tap_count() == 2 &&
-      target->delegate()->GetNonClientComponent(event->location()) ==
-          HTCAPTION) {
+      wm::GetNonClientComponent(target, event->location()) == HTCAPTION) {
     ShellPort::Get()->RecordUserMetricsAction(
         UMA_PANEL_MINIMIZE_CAPTION_GESTURE);
     wm::GetWindowState(target)->Minimize();