Use unified invalidation path for repaint-only style changes

Source/core/rendering/RenderLayer.cpp

Index: Source/core/rendering/RenderLayer.cpp
diff --git a/Source/core/rendering/RenderLayer.cpp b/Source/core/rendering/RenderLayer.cpp
index 1e5511b19742d4e9bd08e8c7fadc492708fdeeaa..c83e8db093200e05c2121f8c2ec452d93dd3b75e 100644
--- a/Source/core/rendering/RenderLayer.cpp
+++ b/Source/core/rendering/RenderLayer.cpp
@@ -3772,6 +3772,21 @@ void RenderLayer::computeSelfHitTestRects(LayerHitTestRects& rects) const
     }
 }
 
+void RenderLayer::setShouldDoFullPaintInvalidationIncludingNonCompositingDescendants()
+{
+    // FIXME: For objects whose invalidateTreeIfNeeded won't invalidate themselves,
+    // we still need to invalidate now. crbug.com/394133.
+    if (renderer()->canSelfInvalidateDuringTreeInvalidation())
+        renderer()->setShouldDoFullPaintInvalidation(true);
+    else
+        renderer()->paintInvalidationForWholeRenderer();
+
+    for (RenderLayer* child = firstChild(); child; child = child->nextSibling()) {
+        if (child->compositingState() != PaintsIntoOwnBacking && child->compositingState() != PaintsIntoGroupedBacking)
+            child->setShouldDoFullPaintInvalidationIncludingNonCompositingDescendants();
+    }
+}
+
 DisableCompositingQueryAsserts::DisableCompositingQueryAsserts()
     : m_disabler(gCompositingQueryMode, CompositingQueriesAreAllowed) { }