Allow the cursor to warp even when a window is dragged

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 8d0ee8d38a220e00acce834ab668794968431b25..3a328e4897452abb3a1b745770871da5ed4e77ea 100644
--- a/ash/wm/toplevel_window_event_filter.cc
+++ b/ash/wm/toplevel_window_event_filter.cc
@@ -14,6 +14,7 @@
 #include "base/message_loop.h"
 #include "base/run_loop.h"
 #include "ui/aura/client/aura_constants.h"
+#include "ui/aura/client/screen_position_client.h"
 #include "ui/aura/env.h"
 #include "ui/aura/event.h"
 #include "ui/aura/root_window.h"
@@ -43,7 +44,7 @@ gfx::Point ConvertPointToParent(aura::Window* window,
   return result;
 }
 
-}
+}  // namespace
 
 ToplevelWindowEventFilter::ToplevelWindowEventFilter(aura::Window* owner)
     : in_move_loop_(false),
@@ -270,8 +271,20 @@ bool ToplevelWindowEventFilter::HandleDrag(aura::Window* target,
 
   if (!window_resizer_.get())
     return false;
-  window_resizer_->Drag(ConvertPointToParent(target, event->location()),
-                        event->flags());
+
+  gfx::Point location_in_root(event->location());
+  aura::Window::ConvertPointToWindow(
+      target, target->GetRootWindow(), &location_in_root);
+
+  // Get the root window where the cursor is currently on, then pass the cursor
+  // location in the screen coordinates to |window_resizer_|.
+  std::pair<aura::RootWindow*, gfx::Point> actual_location =
+      Shell::GetInstance()->NormalizeLocationInDragEvent(
+          target->GetRootWindow(), location_in_root);
+  aura::client::GetScreenPositionClient(actual_location.first)->
+      ConvertPointToScreen(actual_location.first, &actual_location.second);
+
+  window_resizer_->Drag(actual_location.second, event->flags());
   return true;
 }