Remove useless null checks from Node::document() call sites

Source/core/html/HTMLElement.cpp

Index: Source/core/html/HTMLElement.cpp
diff --git a/Source/core/html/HTMLElement.cpp b/Source/core/html/HTMLElement.cpp
index 1200546e88092bbaeeee22b4d2782a101157a719..f3c583e274073b2b4dc1f8bd9b53896217a91d88 100644
--- a/Source/core/html/HTMLElement.cpp
+++ b/Source/core/html/HTMLElement.cpp
@@ -929,7 +929,7 @@ void HTMLElement::calculateAndAdjustDirectionality()
 
 void HTMLElement::adjustDirectionalityIfNeededAfterChildrenChanged(Node* beforeChange, int childCountDelta)
 {
-    if ((!document() || document()->renderer()) && childCountDelta < 0) {
+    if (document()->renderer() && childCountDelta < 0) {
         Node* node = beforeChange ? NodeTraversal::nextSkippingChildren(beforeChange) : 0;
         for (int counter = 0; node && counter < childCountDelta; counter++, node = NodeTraversal::nextSkippingChildren(node)) {
             if (elementAffectsDirectionality(node))