Dragging panels near screen edge

ash/wm/panels/panel_window_resizer.cc

Index: ash/wm/panels/panel_window_resizer.cc
diff --git a/ash/wm/panels/panel_window_resizer.cc b/ash/wm/panels/panel_window_resizer.cc
index 1c054b4c36f20c00128ae0d763a53588d1e62589..997320b9fdb38f9a4068c33e82c026b1c44747ba 100644
--- a/ash/wm/panels/panel_window_resizer.cc
+++ b/ash/wm/panels/panel_window_resizer.cc
@@ -64,13 +64,11 @@ void PanelWindowResizer::Drag(const gfx::Point& location, int event_flags) {
     did_move_or_resize_ = true;
     StartedDragging();
   }
-  gfx::Point location_in_screen = location;
-  wm::ConvertPointToScreen(GetTarget()->parent(), &location_in_screen);
 
   // Check if the destination has changed displays.
   gfx::Screen* screen = Shell::GetScreen();
   const gfx::Display dst_display =
-      screen->GetDisplayNearestPoint(location_in_screen);
+      screen->GetDisplayNearestPoint(last_location_);
   if (dst_display.id() !=
       screen->GetDisplayNearestWindow(panel_container_->GetRootWindow()).id()) {
     // The panel is being dragged to a new display. If the previous container is
@@ -198,9 +196,11 @@ void PanelWindowResizer::StartedDragging() {
     // Attach the panel while dragging placing it in front of other panels.
     GetTarget()->SetProperty(internal::kContinueDragAfterReparent, true);
     GetTarget()->SetProperty(internal::kPanelAttachedKey, true);
+    // We use root window coordinates to ensure that during the drag the panel
+    // is reparented to a container in the root window that has that window.
     GetTarget()->SetDefaultParentByRootWindow(
         GetTarget()->GetRootWindow(),
-        GetTarget()->GetBoundsInScreen());
+        GetTarget()->GetRootWindow()->GetBoundsInScreen());
   }
 }