Allow the user to drag a window from one display to another

ash/wm/window_resizer.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ash/wm/window_resizer.h"
 
 #include "ash/screen_ash.h"
 #include "ash/shell.h"
 #include "ui/aura/client/aura_constants.h"
+#include "ui/aura/client/screen_position_client.h"
 #include "ui/aura/root_window.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_delegate.h"
 #include "ui/base/hit_test.h"
 #include "ui/base/ui_base_types.h"
 #include "ui/compositor/scoped_layer_animation_settings.h"
 #include "ui/gfx/screen.h"
 
 namespace ash {
 
@@ skipping 156 matching lines @@
 // static
 int WindowResizer::AlignToGridRoundDown(int location, int grid_size) {
   if (grid_size <= 1 || location % grid_size == 0)
     return location;
   return location / grid_size * grid_size;
 }
 
 // static
 gfx::Rect WindowResizer::CalculateBoundsForDrag(
     const Details& details,
-    const gfx::Point& location,
+    const gfx::Point& location_in_screen,
     int grid_size) {
   if (!details.is_resizable)
     return details.initial_bounds;
 
+  gfx::Point location = location_in_screen;
+  aura::client::GetScreenPositionClient(details.window->GetRootWindow())->
+      ConvertPointFromScreen(details.window->GetRootWindow(), &location);
+
   int delta_x = location.x() - details.initial_location_in_parent.x();
   int delta_y = location.y() - details.initial_location_in_parent.y();
 
   // The minimize size constraint may limit how much we change the window
   // position.  For example, dragging the left edge to the right should stop
   // repositioning the window when the minimize size is reached.
   gfx::Size size = GetSizeForDrag(details, &delta_x, &delta_y, grid_size);
   gfx::Point origin = GetOriginForDrag(details, delta_x, delta_y);
 
   gfx::Rect new_bounds(origin, size);
@@ skipping 131 matching lines @@
         gfx::Screen::GetDisplayNearestWindow(details.window).bounds().height();
     if (height > max_height) {
       height = max_height;
       *delta_y = -y_multiplier * (details.initial_bounds.height() - max_height);
     }
   }
   return height;
 }
 
 }  // namespace aura