Allow the cursor to warp even when a window is dragged

ash/wm/default_window_resizer.cc

Index: ash/wm/default_window_resizer.cc
diff --git a/ash/wm/default_window_resizer.cc b/ash/wm/default_window_resizer.cc
index 4368c73b88ba14b3230441fe40d1b8a83ebc0d22..c0a71f25eae18f21731334d57512870c27f9154e 100644
--- a/ash/wm/default_window_resizer.cc
+++ b/ash/wm/default_window_resizer.cc
@@ -5,6 +5,7 @@
 #include "ash/wm/default_window_resizer.h"
 
 #include "ash/shell.h"
+#include "ash/wm/coordinate_conversion.h"
 #include "ash/wm/cursor_manager.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/env.h"
@@ -33,6 +34,14 @@ DefaultWindowResizer::Create(aura::Window* window,
 }
 
 void DefaultWindowResizer::Drag(const gfx::Point& location, int event_flags) {
+  std::pair<aura::RootWindow*, gfx::Point> actual_location =
+      wm::GetRootWindowRelativeToWindow(details_.window->parent(), location);
+
+  // TODO(mazda|yusukes): Implement dragging an item from one display to another
+  aura::RootWindow* current_root = actual_location.first;
+  if (current_root != details_.window->GetRootWindow())
+    return;
+
   int grid_size = event_flags & ui::EF_CONTROL_DOWN ?
                   0 : ash::Shell::GetInstance()->GetGridSize();
   gfx::Rect bounds(CalculateBoundsForDrag(details_, location, grid_size));