Improve outline bounds estimation in InlinePainter

Source/core/paint/InlinePainter.h

Index: Source/core/paint/InlinePainter.h
diff --git a/Source/core/paint/InlinePainter.h b/Source/core/paint/InlinePainter.h
index 426fbfb281024e76354370cd453a1f6b330b287b..c61663e54bfeeee60be2f23fddf2c0ace4501494 100644
--- a/Source/core/paint/InlinePainter.h
+++ b/Source/core/paint/InlinePainter.h
@@ -6,6 +6,7 @@
 #define InlinePainter_h
 
 #include "core/style/ComputedStyleConstants.h"
+#include "wtf/Vector.h"
 
 namespace blink {
 
@@ -24,6 +25,7 @@ public:
     void paintOutline(const PaintInfo&, const LayoutPoint& paintOffset);
 
 private:
+    LayoutRect outlinePaintRect(const Vector<LayoutRect>&, const LayoutPoint& paintOffset) const;
     void paintOutlineForLine(GraphicsContext*, const LayoutPoint&, const LayoutRect& prevLine, const LayoutRect& thisLine,
         const LayoutRect& nextLine, const Color);
     LayoutInline& m_layoutInline;