Expose minContentWidth/maxContentWidth and a callback for computing them.

sky/engine/core/rendering/RenderCustomLayout.cpp

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "sky/engine/config.h"
 #include "sky/engine/core/rendering/RenderCustomLayout.h"
 
 #include "sky/engine/core/rendering/RenderLayer.h"
 #include "sky/engine/core/layout/LayoutCallback.h"
 
 namespace blink {
 
 RenderCustomLayout::RenderCustomLayout(ContainerNode* node)
     : RenderBlock(node)
 {
 }
 
 RenderCustomLayout::~RenderCustomLayout()
 {
 }
 
+void RenderCustomLayout::computePreferredLogicalWidths()
+{
+    ASSERT(node()->isElementNode());
+    toElement(node())->intrinsicWidthsComputer()->handleEvent();
+    clearPreferredLogicalWidthsDirty();
+}
+
 void RenderCustomLayout::layout()
 {
     ASSERT(node()->isElementNode());
     toElement(node())->layoutManager()->handleEvent();
     clearNeedsLayout();
 }
 
 const char* RenderCustomLayout::renderName() const
 {
     return "RenderCustomLayout";
 }
 
 } // namespace blink