Store glyph bounds in WordMeasurement to avoid slow path width calc

Source/core/layout/LayoutText.h

Index: Source/core/layout/LayoutText.h
diff --git a/Source/core/layout/LayoutText.h b/Source/core/layout/LayoutText.h
index 9e01976412305f7a96e47212a9b41c9d2f8902fa..de8cf9e86383f7e96f49d284af6b3a9f51a8bef3 100644
--- a/Source/core/layout/LayoutText.h
+++ b/Source/core/layout/LayoutText.h
@@ -86,8 +86,8 @@ public:
     unsigned textLength() const { return m_text.length(); } // non virtual implementation of length()
     void positionLineBox(InlineBox*);
 
-    virtual float width(unsigned from, unsigned len, const Font&, LayoutUnit xPos, TextDirection, HashSet<const SimpleFontData*>* fallbackFonts = nullptr, GlyphOverflow* = nullptr) const;
-    virtual float width(unsigned from, unsigned len, LayoutUnit xPos, TextDirection, bool firstLine = false, HashSet<const SimpleFontData*>* fallbackFonts = nullptr, GlyphOverflow* = nullptr) const;
+    virtual float width(unsigned from, unsigned len, const Font&, LayoutUnit xPos, TextDirection, HashSet<const SimpleFontData*>* fallbackFonts = nullptr, FloatRect* glyphBounds = nullptr) const;
+    virtual float width(unsigned from, unsigned len, LayoutUnit xPos, TextDirection, bool firstLine = false, HashSet<const SimpleFontData*>* fallbackFonts = nullptr, FloatRect* glyphBounds = nullptr) const;
 
     float minLogicalWidth() const;
     float maxLogicalWidth() const;
@@ -158,7 +158,7 @@ protected:
 
 private:
     void computePreferredLogicalWidths(float leadWidth);
-    void computePreferredLogicalWidths(float leadWidth, HashSet<const SimpleFontData*>& fallbackFonts, GlyphOverflow&);
+    void computePreferredLogicalWidths(float leadWidth, HashSet<const SimpleFontData*>& fallbackFonts, FloatRect& glyphBounds);
 
     bool computeCanUseSimpleFontCodePath() const;
 
@@ -173,7 +173,7 @@ private:
 
     void deleteTextBoxes();
     bool containsOnlyWhitespace(unsigned from, unsigned len) const;
-    float widthFromCache(const Font&, int start, int len, float xPos, TextDirection, HashSet<const SimpleFontData*>* fallbackFonts, GlyphOverflow*) const;
+    float widthFromFont(const Font&, int start, int len, float leadWidth, float textWidthSoFar, TextDirection, HashSet<const SimpleFontData*>* fallbackFonts, FloatRect* glyphBoundsAccumulation) const;
 
     void secureText(UChar mask);