Update paint property subtrees on paint offset changes

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

Index: third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.h
diff --git a/third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.h b/third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.h
index 350073f43cf0682d3f919badd70ad5b98878da83..719b316d5f1b51ab171483b734aa7c196907baf5 100644
--- a/third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.h
+++ b/third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.h
@@ -96,8 +96,9 @@ class PaintPropertyTreeBuilder {
   // date.
   void updateProperties(FrameView&, PaintPropertyTreeBuilderContext&);
 
-  // Update the context to account for positioning. This can affect the
-  // current paint offset, for example, but no paint properties are updated.
+  // Update the context to account for positioning. No paint properties are
+  // updated but this can affect the current paint offset which will force a
+  // subtree update.
   void updateContextForBoxPosition(const LayoutObject&,
                                    PaintPropertyTreeBuilderContext&);