GeometryMapper: Support computing visual rects in spaces that are not direct ancestors.

third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.cpp

Index: third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.cpp
diff --git a/third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.cpp b/third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.cpp
index 2823cc71fc0a171897078a01fb939785dc88bc5e..4f6df8dd6bd5026f80d688a498fdfd81b5793594 100644
--- a/third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.cpp
+++ b/third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.cpp
@@ -162,17 +162,10 @@ void PaintPropertyTreeBuilder::updateCssClip(const LayoutObject& object, PaintPr
 
 void PaintPropertyTreeBuilder::updateLocalBorderBoxContext(const LayoutObject& object, const PaintPropertyTreeBuilderContext& context)
 {
-    // Note: Currently only layer painter makes use of the pre-computed context.
-    // This condition may be loosened with no adverse effects beside memory use.
-    if (!object.hasLayer())
-        return;
-
     std::unique_ptr<ObjectPaintProperties::LocalBorderBoxProperties> borderBoxContext =
         wrapUnique(new ObjectPaintProperties::LocalBorderBoxProperties);
     borderBoxContext->paintOffset = context.paintOffset;
-    borderBoxContext->transform = context.currentTransform;
-    borderBoxContext->clip = context.currentClip;
-    borderBoxContext->effect = context.currentEffect;
+    borderBoxContext->propertyTreeState = PropertyTreeState(context.currentTransform, context.currentClip, context.currentEffect);
     object.getMutableForPainting().ensureObjectPaintProperties().setLocalBorderBoxProperties(std::move(borderBoxContext));
 }
 
@@ -384,11 +377,11 @@ static void deriveBorderBoxFromContainerContext(const LayoutObject& object, Pain
 
 void PaintPropertyTreeBuilder::buildTreeNodes(const LayoutObject& object, PaintPropertyTreeBuilderContext& context)
 {
+    object.getMutableForPainting().clearObjectPaintProperties();

[chrishtr, 2016/06/30 16:49:55]

Now allocating an ObjectPaintProperties object for all boxes, to support
representation of property tree states for all
of them in O(1) time. This is needed for paint invalidation.

[pdr., 2016/06/30 21:21:50]

To enforce this and ensure we don't create too many of these, can you add:
if (!object.isBox())
    return;

[chrishtr, 2016/07/01 17:52:24]

Done (in updateLocalBorderBoxContext)

+
     if (!object.isBoxModelObject() && !object.isSVG())
         return;
 
-    object.getMutableForPainting().clearObjectPaintProperties();
-
     deriveBorderBoxFromContainerContext(object, context);
 
     updatePaintOffsetTranslation(object, context);