Refactor PhantomWindowController so that the PhantomWindowController owns the phantom window

ash/wm/gestures/system_pinch_handler.cc

Index: ash/wm/gestures/system_pinch_handler.cc
diff --git a/ash/wm/gestures/system_pinch_handler.cc b/ash/wm/gestures/system_pinch_handler.cc
index 83511a6471a66c07b16346feedf00f0539e11a06..981dc24a77e0b50a7e17108e48ffd11936e60909 100644
--- a/ash/wm/gestures/system_pinch_handler.cc
+++ b/ash/wm/gestures/system_pinch_handler.cc
@@ -30,7 +30,6 @@ const int SystemPinchHandler::kSystemGesturePoints = 4;
 
 SystemPinchHandler::SystemPinchHandler(aura::Window* target)
     : target_(target),
-      phantom_(target),
       phantom_state_(PHANTOM_WINDOW_NORMAL),
       pinch_factor_(1.) {
   widget_ = views::Widget::GetWidgetForNativeWindow(target_);
@@ -72,13 +71,16 @@ SystemGestureStatus SystemPinchHandler::ProcessGestureEvent(
       pinch_factor_ *= event.details().scale();
       gfx::Rect bounds =
           GetPhantomWindowScreenBounds(target_, event.location());
-      if (phantom_state_ != PHANTOM_WINDOW_NORMAL || phantom_.IsShowing())
-        phantom_.Show(bounds);
+      if (phantom_state_ != PHANTOM_WINDOW_NORMAL || phantom_.get()) {
+        if (!phantom_.get())
+          phantom_.reset(new internal::PhantomWindowController(target_));
+        phantom_->Show(bounds);
+     }
       break;
     }
 
     case ui::ET_GESTURE_MULTIFINGER_SWIPE: {
-      phantom_.Hide();
+      phantom_.reset();
       pinch_factor_ = 1.0;
       phantom_state_ = PHANTOM_WINDOW_NORMAL;