[Line Layout API] Convert a few RootInlineBox uses of layoutObject()

third_party/WebKit/Source/core/layout/LayoutBlockFlow.h

Index: third_party/WebKit/Source/core/layout/LayoutBlockFlow.h
diff --git a/third_party/WebKit/Source/core/layout/LayoutBlockFlow.h b/third_party/WebKit/Source/core/layout/LayoutBlockFlow.h
index 95b43d8b4b6f930040d005bd574870cd3620dbb8..cc1dc25e817df631e96b0409d12769b80ca4dd61 100644
--- a/third_party/WebKit/Source/core/layout/LayoutBlockFlow.h
+++ b/third_party/WebKit/Source/core/layout/LayoutBlockFlow.h
@@ -209,9 +209,9 @@ public:
 
     bool shouldPaintSelectionGaps() const final;
     LayoutRect logicalLeftSelectionGap(const LayoutBlock* rootBlock, const LayoutPoint& rootBlockPhysicalPosition, const LayoutSize& offsetFromRootBlock,
-        const LayoutObject* selObj, LayoutUnit logicalLeft, LayoutUnit logicalTop, LayoutUnit logicalHeight, const PaintInfo*) const;
+        const LineLayoutItem selObj, LayoutUnit logicalLeft, LayoutUnit logicalTop, LayoutUnit logicalHeight, const PaintInfo*) const;
     LayoutRect logicalRightSelectionGap(const LayoutBlock* rootBlock, const LayoutPoint& rootBlockPhysicalPosition, const LayoutSize& offsetFromRootBlock,
-        const LayoutObject* selObj, LayoutUnit logicalRight, LayoutUnit logicalTop, LayoutUnit logicalHeight, const PaintInfo*) const;
+        const LineLayoutItem selObj, LayoutUnit logicalRight, LayoutUnit logicalTop, LayoutUnit logicalHeight, const PaintInfo*) const;
     void getSelectionGapInfo(SelectionState, bool& leftGap, bool& rightGap) const;
 
     LayoutRect selectionRectForPaintInvalidation(const LayoutBoxModelObject* paintInvalidationContainer) const final;