Implement incremental paint property tree rebuilding

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

Index: third_party/WebKit/Source/core/layout/LayoutObject.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutObject.cpp b/third_party/WebKit/Source/core/layout/LayoutObject.cpp
index a23fb37c132ecd3600fe51a9c70cc3bbea488fe6..60a840c729f4d2d07fbb9398a068a5bb7f2e1b7c 100644
--- a/third_party/WebKit/Source/core/layout/LayoutObject.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutObject.cpp
@@ -1477,6 +1477,11 @@ StyleDifference LayoutObject::adjustStyleDifference(
       // for changed paint property or paint order. Raster invalidation will be
       // issued if needed during paint.
       ObjectPaintInvalidator(*this).slowSetPaintingLayerNeedsRepaint();
+
+      // When transform, opacity, etc. change, paint properties will also change
+      // so we need to mark this object as needing an update.
+      // TODO(pdr): Also update in the non-spv2 codepath?

[pdr., 2016/11/11 23:50:27]

Xianzhu, do we need to do this (also setNeedsPaintPropertyUpdate in the other
half of this conditional) for spinvalidation?

[Xianzhu, 2016/11/12 00:30:48]

We still need to go through the traditional path for spinvalidation because
visual rects are relative to paint invalidation containers.

+      getMutableForPainting().setNeedsPaintPropertyUpdate();
     }
   } else {
     // If transform changed, and the layer does not paint into its own separate