COMPLETED PREVIEW Migrate to Display Placement

ui/gfx/display_layout.h

Index: ui/gfx/display_layout.h
diff --git a/ui/gfx/display_layout.h b/ui/gfx/display_layout.h
index 8d1d57ec7270764e1e154cb3dc061f6e04102e4f..c7215627812d1747d6e08c0a1d929e120e30124e 100644
--- a/ui/gfx/display_layout.h
+++ b/ui/gfx/display_layout.h
@@ -55,14 +55,27 @@ struct GFX_EXPORT DisplayPlacement {
   enum Position { TOP, RIGHT, BOTTOM, LEFT };
   Position position;
 
-  // The offset of the position of the secondary display. The offset is
-  // based on the top/left edge of the primary display.
+  // The offset of the position with respect to the parent.
   int offset;
 
-  explicit DisplayPlacement(const DisplayPlacement& placement);
+  // Determines if the offset is relative to the TOP_LEFT or the BOTTOM_RIGHT.
+  // Defaults to TOP_LEFT.
+  enum OffsetReference { TOP_LEFT, BOTTOM_RIGHT };
+  OffsetReference offset_reference;
+
   DisplayPlacement(Position position, int offset);
+  DisplayPlacement(Position position,
+                   int offset,
+                   OffsetReference offset_reference);
+  DisplayPlacement(int64_t display_id,
+                   int64_t parent_display_id,
+                   Position position,
+                   int offset,
+                   OffsetReference offset_reference);
   DisplayPlacement();
 
+  DisplayPlacement(const DisplayPlacement& placement);
+
   DisplayPlacement& Swap();
 
   std::string ToString() const;
@@ -77,6 +90,19 @@ class GFX_EXPORT DisplayLayout final {
   DisplayLayout();
   ~DisplayLayout();
 
+  // Applies the layout and updates the bounds of displays in |display_list|.
+  // |updated_ids| contains the ids for displays whose bounds have changed.
+  void ApplyToDisplayList(DisplayList* display_list,
+                          std::vector<int64_t>* updated_ids,
+                          int minimum_offset_overlap) const;
+
+  // Apply the display placement to the display layout.
+  // Returns true if the display bounds has been updated.
+  bool ApplyDisplayPlacement(const gfx::DisplayPlacement& placement,
+                             gfx::DisplayList* display_list,
+                             int minimum_offset_overlap) const;
+
+
   // Validates the layout object.
   static bool Validate(const DisplayIdList& list, const DisplayLayout& layout);