Desktop Aura: Allow tab drags out of window.

ash/wm/toplevel_window_event_filter.cc

Index: ash/wm/toplevel_window_event_filter.cc
diff --git a/ash/wm/toplevel_window_event_filter.cc b/ash/wm/toplevel_window_event_filter.cc
index a8bc6dc44728b0099d2925f60960045dd65fa9a7..a83f9a0baa1b189c55c9000c5836e30af1d8fa4a 100644
--- a/ash/wm/toplevel_window_event_filter.cc
+++ b/ash/wm/toplevel_window_event_filter.cc
@@ -202,7 +202,8 @@ ui::GestureStatus ToplevelWindowEventFilter::PreHandleGestureEvent(
   return ui::GESTURE_STATUS_CONSUMED;
 }
 
-void ToplevelWindowEventFilter::RunMoveLoop(aura::Window* source) {
+void ToplevelWindowEventFilter::RunMoveLoop(aura::Window* source,
+                                            const gfx::Point& drag_offset) {
   DCHECK(!in_move_loop_);  // Can only handle one nested loop at a time.
   in_move_loop_ = true;
   aura::RootWindow* root_window = source->GetRootWindow();