Persist invalidation sets on detach root

third_party/WebKit/Source/core/css/invalidation/StyleInvalidator.cpp

Index: third_party/WebKit/Source/core/css/invalidation/StyleInvalidator.cpp
diff --git a/third_party/WebKit/Source/core/css/invalidation/StyleInvalidator.cpp b/third_party/WebKit/Source/core/css/invalidation/StyleInvalidator.cpp
index 6cd632a3bcb8d1de8cc3cd032d7a8a92c4c5a921..d8543093af7228db4c4da7979bf302ec2a8260e4 100644
--- a/third_party/WebKit/Source/core/css/invalidation/StyleInvalidator.cpp
+++ b/third_party/WebKit/Source/core/css/invalidation/StyleInvalidator.cpp
@@ -43,23 +43,22 @@ void StyleInvalidator::invalidate(Document& document)
 void StyleInvalidator::scheduleInvalidationSetsForElement(const InvalidationLists& invalidationLists, Element& element)
 {
     ASSERT(element.inActiveDocument());
-    if (element.styleChangeType() >= SubtreeStyleChange)
-        return;
-
     bool requiresDescendantInvalidation = false;
 
-    for (auto& invalidationSet : invalidationLists.descendants) {
-        if (invalidationSet->wholeSubtreeInvalid()) {
-            element.setNeedsStyleRecalc(SubtreeStyleChange, StyleChangeReasonForTracing::create(StyleChangeReason::StyleInvalidator));
-            clearInvalidation(element);
-            return;
-        }
+    if (element.styleChangeType() < SubtreeStyleChange) {
+        for (auto& invalidationSet : invalidationLists.descendants) {
+            if (invalidationSet->wholeSubtreeInvalid()) {
+                element.setNeedsStyleRecalc(SubtreeStyleChange, StyleChangeReasonForTracing::create(StyleChangeReason::StyleInvalidator));
+                requiresDescendantInvalidation = false;
+                break;
+            }
 
-        if (invalidationSet->invalidatesSelf())
-            element.setNeedsStyleRecalc(LocalStyleChange, StyleChangeReasonForTracing::create(StyleChangeReason::StyleInvalidator));
+            if (invalidationSet->invalidatesSelf())
+                element.setNeedsStyleRecalc(LocalStyleChange, StyleChangeReasonForTracing::create(StyleChangeReason::StyleInvalidator));
 
-        if (!invalidationSet->isEmpty())
-            requiresDescendantInvalidation = true;
+            if (!invalidationSet->isEmpty())
+                requiresDescendantInvalidation = true;
+        }
     }
 
     if (!requiresDescendantInvalidation && (invalidationLists.siblings.isEmpty() || !element.nextSibling()))