Don't invalidate rect if it's covered by fully invalidated parent's visual rect

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

Index: third_party/WebKit/Source/core/paint/ObjectPaintInvalidator.h
diff --git a/third_party/WebKit/Source/core/paint/ObjectPaintInvalidator.h b/third_party/WebKit/Source/core/paint/ObjectPaintInvalidator.h
index 61ca4f87a2244537a5e4d85c53209f8a44cb46e4..80f339a659278a45ca48eb8d2288aae8bde0d0c3 100644
--- a/third_party/WebKit/Source/core/paint/ObjectPaintInvalidator.h
+++ b/third_party/WebKit/Source/core/paint/ObjectPaintInvalidator.h
@@ -112,8 +112,12 @@ class ObjectPaintInvalidatorWithContext : public ObjectPaintInvalidator {
                             const LayoutRect& oldVisualRect,
                             const LayoutRect& newVisualRect);
 
+  void invalidatePaintRectangleWithContext(const LayoutRect&,
+                                           PaintInvalidationReason);
+
  private:
   void invalidateSelectionIfNeeded(PaintInvalidationReason);
+  bool parentFullyInvalidatedOnSameBacking();
 
   const PaintInvalidatorContext& m_context;
 };