Introducing LayoutObject::mapToVisibleRectInContainerSpace

third_party/WebKit/Source/core/layout/LayoutObject.h

Index: third_party/WebKit/Source/core/layout/LayoutObject.h
diff --git a/third_party/WebKit/Source/core/layout/LayoutObject.h b/third_party/WebKit/Source/core/layout/LayoutObject.h
index 709f3bba05d33abb9efaceb114c0ba7a0e2ce02f..ae9e41aeaf2cafcdb7bf506b76a85c82231f3a96 100644
--- a/third_party/WebKit/Source/core/layout/LayoutObject.h
+++ b/third_party/WebKit/Source/core/layout/LayoutObject.h
@@ -1083,9 +1083,10 @@ public:
     virtual LayoutRect absoluteClippedOverflowRect() const;
     virtual LayoutRect clippedOverflowRectForPaintInvalidation(const LayoutBoxModelObject* paintInvalidationContainer, const PaintInvalidationState* = nullptr) const;
 
-    // Given a rect in the object's coordinate space, compute a rect suitable for invalidating paints of
-    // that rect in the coordinate space of paintInvalidationContainer.
-    virtual void mapRectToPaintInvalidationBacking(const LayoutBoxModelObject* paintInvalidationContainer, LayoutRect&, const PaintInvalidationState*) const;
+    // Given a rect in the object's coordinate space, compute a rect suitable for invalidating paints of that
+    // rect in the coordinate space of paintInvalidationContainer.  If intermediate containers have overflow

[chrishtr, 2015/12/10 19:17:13]

clipping or scrolling of any kind

[szager1, 2015/12/10 20:25:09]

Done.

+    // clipping, it is applied; but overflow clipping is *not* applied for paintInvalidationContainer itself.

[chrishtr, 2015/12/10 19:17:13]

But the scroll offset of paintInvalidationContainer does get applied.

[szager1, 2015/12/10 20:25:09]

Isn't that redundant?  The method name already indicates that it maps the rect
to the container space.

[chrishtr, 2015/12/10 21:19:40]

I guess. Seems harmless to me but ok.

+    virtual void visibleRectInContainerSpace(const LayoutBoxModelObject* paintInvalidationContainer, LayoutRect&, const PaintInvalidationState*) const;

[chrishtr, 2015/12/10 19:13:35]

s/paintInvalidationContainer/container/

Since this method does not return a value, and instead mutates one of them,
maybe a better name is mapToVisibleRectInContainerSpace().

[szager1, 2015/12/10 20:25:09]

Done.

 
     // Return the offset to the column in which the specified point (in flow-thread coordinates)
     // lives. This is used to convert a flow-thread point to a visual point.