Detect and fix overlapping displays

ui/display/display_layout.h

 // Copyright 2016 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.
 
 #ifndef UI_DISPLAY_DISPLAY_LAYOUT_H_
 #define UI_DISPLAY_DISPLAY_LAYOUT_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 68 matching lines @@
 };
 
 class DISPLAY_EXPORT DisplayLayout final {
  public:
   DisplayLayout();
   ~DisplayLayout();
 
   // Applies the layout to the displays in |display_list|.
   // |updated_ids| (optional) contains the ids for displays whose bounds have
   // changed. |minimum_offset_overlap| represents the minimum required overlap
-  // between displays.
+  // between displays. Any overlap between displays will be fixed, and the
+  // display placement will be fixed.
   void ApplyToDisplayList(Displays* display_list,
                           std::vector<int64_t>* updated_ids,
-                          int minimum_offset_overlap) const;
+                          int minimum_offset_overlap);
 
   // Validates the layout object.
   static bool Validate(const DisplayIdList& list, const DisplayLayout& layout);
 
   std::vector<DisplayPlacement> placement_list;
 
   // True if displays are mirrored.
   bool mirrored;
 
   // True if multi displays should default to unified mode.
@@ skipping 21 matching lines @@
   static bool ApplyDisplayPlacement(const DisplayPlacement& placement,
                                     Displays* display_list,
                                     int minimum_offset_overlap);
 
   DISALLOW_COPY_AND_ASSIGN(DisplayLayout);
 };
 
 }  // namespace display
 
 #endif  // UI_DISPLAY_DISPLAY_LAYOUT_H_