Adjust constness to avoid const_cast.

third_party/WebKit/Source/core/layout/LayoutBlock.cpp

Index: third_party/WebKit/Source/core/layout/LayoutBlock.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutBlock.cpp b/third_party/WebKit/Source/core/layout/LayoutBlock.cpp
index bc46a2b38b836012f8081342507ed02f5b264f16..8c7a41f3163febe910500daf647efe45bb838785 100644
--- a/third_party/WebKit/Source/core/layout/LayoutBlock.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutBlock.cpp
@@ -1999,9 +1999,9 @@ int LayoutBlock::inlineBlockBaseline(LineDirectionMode lineDirection) const
     return -1;
 }
 
-LayoutBlock* LayoutBlock::enclosingFirstLineStyleBlock() const
+const LayoutBlock* LayoutBlock::enclosingFirstLineStyleBlock() const
 {
-    LayoutBlock* firstLineBlock = const_cast<LayoutBlock*>(this);
+    const LayoutBlock* firstLineBlock = this;
     bool hasPseudo = false;
     while (true) {
         hasPseudo = firstLineBlock->style()->hasPseudoStyle(PseudoIdFirstLine);
@@ -2024,10 +2024,10 @@ LayoutBlock* LayoutBlock::enclosingFirstLineStyleBlock() const
     return firstLineBlock;
 }
 
-LayoutBlockFlow* LayoutBlock::nearestInnerBlockWithFirstLine() const
+LayoutBlockFlow* LayoutBlock::nearestInnerBlockWithFirstLine()

[eae, 2016/05/10 15:40:54]

Can this return a const LayoutBlockFlow?

[mstensho (USE GERRIT), 2016/05/10 15:58:16]

The caller calls non-const methods on the returned object, so it doesn't seem
like a good idea.

 {
     if (childrenInline())
-        return toLayoutBlockFlow(const_cast<LayoutBlock*>(this));
+        return toLayoutBlockFlow(this);

[eae, 2016/05/10 15:40:54]

Could we add a const version of toLayoutBlockFlow instead? 

[mstensho (USE GERRIT), 2016/05/10 15:58:16]

The DEFINE_LAYOUT_OBJECT_TYPE_CASTS macro already takes care of that.

     for (LayoutObject* child = firstChild(); child && !child->isFloatingOrOutOfFlowPositioned() && child->isLayoutBlockFlow(); child = toLayoutBlock(child)->firstChild()) {
         if (child->childrenInline())
             return toLayoutBlockFlow(child);