Make InlineBox::renderer() and related subclass methods return reference.

Source/core/rendering/RenderListMarker.cpp

Index: Source/core/rendering/RenderListMarker.cpp
diff --git a/Source/core/rendering/RenderListMarker.cpp b/Source/core/rendering/RenderListMarker.cpp
index b66aab57b30cf57c6c4ca754c52ea88dcb924022..38664a289f4296a83193b2eed0dc61b8be324997 100644
--- a/Source/core/rendering/RenderListMarker.cpp
+++ b/Source/core/rendering/RenderListMarker.cpp
@@ -1117,8 +1117,8 @@ LayoutRect RenderListMarker::localSelectionRect()
     if (!box)
         return LayoutRect(LayoutPoint(), size());
     RootInlineBox* root = inlineBoxWrapper()->root();
-    LayoutUnit newLogicalTop = root->block()->style()->isFlippedBlocksWritingMode() ? inlineBoxWrapper()->logicalBottom() - root->selectionBottom() : root->selectionTop() - inlineBoxWrapper()->logicalTop();
-    if (root->block()->style()->isHorizontalWritingMode())
+    LayoutUnit newLogicalTop = root->block().style()->isFlippedBlocksWritingMode() ? inlineBoxWrapper()->logicalBottom() - root->selectionBottom() : root->selectionTop() - inlineBoxWrapper()->logicalTop();
+    if (root->block().style()->isHorizontalWritingMode())
         return LayoutRect(0, newLogicalTop, width(), root->selectionHeight());
     return LayoutRect(newLogicalTop, 0, root->selectionHeight(), height());
 }