Allow moving cursors between connected displays.

ash/display/unified_mouse_warp_controller.cc

 // Copyright 2015 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/display/unified_mouse_warp_controller.h"
 
 #include <cmath>
 
 #include "ash/display/display_manager.h"
 #include "ash/display/display_util.h"
@@ skipping 113 matching lines @@
                                  ->software_mirroring_display_list();
 
   if (display_list.size() < 2) {
     LOG(ERROR) << "Mirroring Display lost during re-configuration";
     return;
   }
   LOG_IF(ERROR, display_list.size() > 2) << "Only two displays are supported";
 
   const gfx::Display& first = display_list[0];
   const gfx::Display& second = display_list[1];
-  ComputeBoundary(first, second, &first_edge_bounds_in_native_,
-                  &second_edge_bounds_in_native_);
+  bool success = ComputeBoundary(first, second, &first_edge_bounds_in_native_,
+                                 &second_edge_bounds_in_native_);
+  DCHECK(success);
 
   first_edge_bounds_in_native_ =
       GetNativeEdgeBounds(GetMirroringAshWindowTreeHostForDisplayId(first.id()),
                           first_edge_bounds_in_native_);
 
   second_edge_bounds_in_native_ = GetNativeEdgeBounds(
       GetMirroringAshWindowTreeHostForDisplayId(second.id()),
       second_edge_bounds_in_native_);
 }
 
@@ skipping 14 matching lines @@
       in_first_edge ? display_list[0].id() : display_list[1].id();
   AshWindowTreeHost* target_ash_host =
       GetMirroringAshWindowTreeHostForDisplayId(
           in_first_edge ? display_list[1].id() : display_list[0].id());
   MoveCursorTo(target_ash_host, point_in_unified_host,
                update_mouse_location_now);
   return true;
 }
 
 }  // namespace ash