Plumb selection bounds as a single unit

public/platform/WebLayerTreeView.h

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 25 matching lines @@
 
 class SkBitmap;
 
 namespace blink {
 
 class WebCompositeAndReadbackAsyncCallback;
 class WebCompositorAnimationTimeline;
 class WebLayer;
 struct WebPoint;
 struct WebSelectionBound;
+class WebSelection;
 class WebWidget;
 
 class WebLayerTreeView {
 public:
     virtual ~WebLayerTreeView() { }
 
     // Initialization and lifecycle --------------------------------------
 
     // Sets the root of the tree. The root is set by way of the constructor.
     virtual void setRootLayer(const WebLayer&) = 0;
@@ skipping 70 matching lines @@
 
     // Identify key layers to the compositor when using the pinch virtual viewport.
     virtual void registerViewportLayers(
         const WebLayer* overscrollElasticityLayer,
         const WebLayer* pageScaleLayer,
         const WebLayer* innerViewportScrollLayer,
         const WebLayer* outerViewportScrollLayer) { }
     virtual void clearViewportLayers() { }
 
     // Used to update the active selection bounds.
-    // If the (empty) selection is an insertion point, |start| and |end| will be identical with type |Caret|.
-    // If the (non-empty) selection has mixed RTL/LTR text, |start| and |end| may share the same type,
-    // |SelectionLeft| or |SelectionRight|.
+    // FIXME: Remove this overload when downstream consumers have been updated to use WebSelection, crbug.com/466672.
     virtual void registerSelection(const WebSelectionBound& start, const WebSelectionBound& end) { }
+    virtual void registerSelection(const WebSelection&) { }
     virtual void clearSelection() { }
 
     // Debugging / dangerous ---------------------------------------------
 
     // Toggles the FPS counter in the HUD layer
     virtual void setShowFPSCounter(bool) { }
 
     // Toggles the paint rects in the HUD layer
     virtual void setShowPaintRects(bool) { }
 
     // Toggles the debug borders on layers
     virtual void setShowDebugBorders(bool) { }
 
     // Toggles continuous painting
     virtual void setContinuousPaintingEnabled(bool) { }
 
     // Toggles scroll bottleneck rects on the HUD layer
     virtual void setShowScrollBottleneckRects(bool) { }
 };
 
 } // namespace blink
 
 #endif // WebLayerTreeView_h