[WIP] Implement :dir()

third_party/WebKit/Source/core/dom/Element.cpp

Index: third_party/WebKit/Source/core/dom/Element.cpp
diff --git a/third_party/WebKit/Source/core/dom/Element.cpp b/third_party/WebKit/Source/core/dom/Element.cpp
index 4ae2e5d3a125ab92f99efd46fe859e6352e0f4ae..eba4c90a4be4051a48900e0134e01947de043c12 100644
--- a/third_party/WebKit/Source/core/dom/Element.cpp
+++ b/third_party/WebKit/Source/core/dom/Element.cpp
@@ -3640,6 +3640,31 @@ bool Element::supportsStyleSharing() const
     return true;
 }
 
+TextDirection Element::directionality() const
+{
+    if (isHTMLElement() && toHTMLElement(this)->hasDirectionAuto()) {
+        CachedTextDirection direction = const_cast<Element*>(this)->ensureUniqueElementData().directionality();
+        if (direction == CachedTextDirection::NotAutoOrNotCached) {
+            toHTMLElement(this)->cacheDirectionalityForDirAuto();
+            direction = elementData()->directionality();
+            DCHECK(direction != CachedTextDirection::NotAutoOrNotCached);
+        }
+        if (direction == CachedTextDirection::AutoLTR)
+            return LTR;
+        return RTL;
+    }
+
+    if (equalIgnoringCase(fastGetAttribute(dirAttr), "ltr"))
+        return LTR;
+    if (equalIgnoringCase(fastGetAttribute(dirAttr), "rtl"))
+        return RTL;
+
+    const Element* parent = FlatTreeTraversal::parentElement(*this);
+    if (parent)
+        return parent->directionality();
+    return LTR;
+}
+
 void Element::logAddElementIfIsolatedWorldAndInDocument(const char element[], const QualifiedName& attr1)
 {
     if (!inShadowIncludingDocument())