Underline Thickness is not uniform

Source/core/rendering/InlineTextBox.h

Index: Source/core/rendering/InlineTextBox.h
diff --git a/Source/core/rendering/InlineTextBox.h b/Source/core/rendering/InlineTextBox.h
index 69b2a1d756b7b46c8c1a6644f7f9326de83774fd..372a4e99acb5b2c8a6d4aa0d5025438e982d1766 100644
--- a/Source/core/rendering/InlineTextBox.h
+++ b/Source/core/rendering/InlineTextBox.h
@@ -50,6 +50,7 @@ public:
         , m_start(0)
         , m_len(0)
         , m_truncation(cNoTruncation)
+        , m_textDecorationThickness(0)
     {
     }
 
@@ -119,6 +120,8 @@ public:
 
 protected:
     virtual void paint(PaintInfo&, const LayoutPoint&, LayoutUnit lineTop, LayoutUnit lineBottom) OVERRIDE;
+    virtual void paintDecorationStyle(PaintInfo&, const LayoutPoint&, LayoutUnit lineTop, LayoutUnit lineBottom, float decorationThickness) OVERRIDE;
+    virtual void getPaintDecorationSyle(PaintInfo&, const LayoutPoint&, float *) OVERRIDE;
     virtual bool nodeAtPoint(const HitTestRequest&, HitTestResult&, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset, LayoutUnit lineTop, LayoutUnit lineBottom) OVERRIDE;
 
 public:
@@ -175,6 +178,8 @@ private:
     unsigned short m_truncation; // Where to truncate when text overflow is applied.  We use special constants to
                       // denote no truncation (the whole run paints) and full truncation (nothing paints at all).
 
+    float m_textDecorationThickness;
+
 protected:
     void paintCompositionBackground(GraphicsContext*, const FloatPoint& boxOrigin, RenderStyle*, const Font&, int startPos, int endPos);
     void paintDocumentMarkers(GraphicsContext*, const FloatPoint& boxOrigin, RenderStyle*, const Font&, bool background);
@@ -185,14 +190,18 @@ protected:
     virtual void paintTextMatchMarker(GraphicsContext*, const FloatPoint& boxOrigin, DocumentMarker*, RenderStyle*, const Font&);
 
 private:
-    void paintDecoration(GraphicsContext*, const FloatPoint& boxOrigin, TextDecoration, const ShadowList*);
+    void paintDecoration(GraphicsContext*, const FloatPoint& boxOrigin, TextDecoration, const ShadowList*,  float decorationThickness = 0);
     void paintSelection(GraphicsContext*, const FloatPoint& boxOrigin, RenderStyle*, const Font&, Color textColor);
+    bool isLogicalStartEndCorrect(PaintInfo& , const LayoutPoint&);
 
     TextRun::ExpansionBehavior expansionBehavior() const
     {
         return (canHaveLeadingExpansion() ? TextRun::AllowLeadingExpansion : TextRun::ForbidLeadingExpansion)
             | (expansion() && nextLeafChild() ? TextRun::AllowTrailingExpansion : TextRun::ForbidTrailingExpansion);
     }
+
+    float getDecorationThickness() { return m_textDecorationThickness; }
+    void setDecorationThickness(float textDecorationThickness) { m_textDecorationThickness = textDecorationThickness; }
 };
 
 DEFINE_INLINE_BOX_TYPE_CASTS(InlineTextBox);