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

Source/core/rendering/RenderBox.cpp

Index: Source/core/rendering/RenderBox.cpp
diff --git a/Source/core/rendering/RenderBox.cpp b/Source/core/rendering/RenderBox.cpp
index 311d9dfc207ec4ce24cc4f5ec6605d55a085f153..760eab0aad7d7832b5fed5c1e2a2aff48cfc7088 100644
--- a/Source/core/rendering/RenderBox.cpp
+++ b/Source/core/rendering/RenderBox.cpp
@@ -1931,7 +1931,7 @@ LayoutSize RenderBox::offsetFromContainer(RenderObject* o, const LayoutPoint& po
 
 InlineBox* RenderBox::createInlineBox()
 {
-    return new InlineBox(this);
+    return new InlineBox(*this);
 }
 
 void RenderBox::dirtyLineBoxes(bool fullLayout)
@@ -1957,7 +1957,7 @@ void RenderBox::positionLineBox(InlineBox* box)
             // our object was inline originally, since otherwise it would have ended up underneath
             // the inlines.
             RootInlineBox* root = box->root();
-            root->block()->setStaticInlinePositionForChild(this, root->lineTopWithLeading(), LayoutUnit::fromFloatRound(box->logicalLeft()));
+            root->block().setStaticInlinePositionForChild(this, root->lineTopWithLeading(), LayoutUnit::fromFloatRound(box->logicalLeft()));
             if (style()->hasStaticInlinePosition(box->isHorizontal()))
                 setChildNeedsLayout(MarkOnlyThis); // Just go ahead and mark the positioned object as needing layout, so it will update its position properly.
         } else {