Make RenderObject::style() return a const object

Source/core/layout/style/LayoutStyle.cpp

Index: Source/core/layout/style/LayoutStyle.cpp
diff --git a/Source/core/layout/style/LayoutStyle.cpp b/Source/core/layout/style/LayoutStyle.cpp
index e7785d0602a70f124e9c430411684cb941e5bf10..fac327f5f9207f5474456e5fdefb507187108d2b 100644
--- a/Source/core/layout/style/LayoutStyle.cpp
+++ b/Source/core/layout/style/LayoutStyle.cpp
@@ -331,8 +331,8 @@ void LayoutStyle::removeCachedPseudoStyle(PseudoId pid)
     if (!m_cachedPseudoStyles)
         return;
     for (size_t i = 0; i < m_cachedPseudoStyles->size(); ++i) {
-        LayoutStyle* pseudoStyle = m_cachedPseudoStyles->at(i).get();
-        if (pseudoStyle->styleType() == pid) {
+        const LayoutStyle& pseudoStyle = *m_cachedPseudoStyles->at(i);
+        if (pseudoStyle.styleType() == pid) {
             m_cachedPseudoStyles->remove(i);
             return;
         }