Update reason after full paint invalidation

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

Index: third_party/WebKit/Source/core/paint/ObjectPaintInvalidator.cpp
diff --git a/third_party/WebKit/Source/core/paint/ObjectPaintInvalidator.cpp b/third_party/WebKit/Source/core/paint/ObjectPaintInvalidator.cpp
index 7949b0458114af0d74af6a1772baaae3230e0757..256b397caaf59cb537cd978413d18291e05fb323 100644
--- a/third_party/WebKit/Source/core/paint/ObjectPaintInvalidator.cpp
+++ b/third_party/WebKit/Source/core/paint/ObjectPaintInvalidator.cpp
@@ -637,6 +637,9 @@ ObjectPaintInvalidatorWithContext::invalidatePaintIfNeededWithComputedReason(
       return PaintInvalidationDelayedFull;
     default:
       DCHECK(isImmediateFullPaintInvalidationReason(reason));
+      // This allows descendants to know the computed reason if it's different
+      // from the original reason before paint invalidation.
+      m_object.getMutableForPainting().setShouldDoFullPaintInvalidation(reason);
       fullyInvalidatePaint(reason, m_context.oldVisualRect,
                            m_object.visualRect());
   }