Store glyph bounds in WordMeasurement to avoid slow path width calc

Source/core/layout/line/BreakingContextInlineHeaders.h

Index: Source/core/layout/line/BreakingContextInlineHeaders.h
diff --git a/Source/core/layout/line/BreakingContextInlineHeaders.h b/Source/core/layout/line/BreakingContextInlineHeaders.h
index 872c379a4897da50c82a8be1341df502e048a916..157128e0698558419f22473c6927a68cbbcbe5d3 100644
--- a/Source/core/layout/line/BreakingContextInlineHeaders.h
+++ b/Source/core/layout/line/BreakingContextInlineHeaders.h
@@ -509,20 +509,16 @@ ALWAYS_INLINE TextDirection textDirectionFromUnicode(WTF::Unicode::Direction dir
         || direction == WTF::Unicode::RightToLeftArabic ? RTL : LTR;
 }
 
-ALWAYS_INLINE float textWidth(LayoutText* text, unsigned from, unsigned len, const Font& font, float xPos, bool collapseWhiteSpace, HashSet<const SimpleFontData*>* fallbackFonts = nullptr)
+ALWAYS_INLINE float textWidth(LayoutText* text, unsigned from, unsigned len, const Font& font, float xPos, bool collapseWhiteSpace, HashSet<const SimpleFontData*>* fallbackFonts = nullptr, FloatRect* glyphBounds = nullptr)
 {
-    if ((!from && len == text->textLength()) || text->style()->hasTextCombine()) {
-        GlyphOverflow glyphOverflow;
-        return text->width(from, len, font, xPos, text->style()->direction(), fallbackFonts,
-            // LayoutText caches fallbackFonts and glyphOverflow together, and requires them to be both null or both non-null.
-            fallbackFonts ? &glyphOverflow : nullptr);
-    }
+    if ((!from && len == text->textLength()) || text->style()->hasTextCombine())
+        return text->width(from, len, font, xPos, text->style()->direction(), fallbackFonts, glyphBounds);
 
     TextRun run = constructTextRun(text, font, text, from, len, text->styleRef());
     run.setCodePath(text->canUseSimpleFontCodePath() ? TextRun::ForceSimple : TextRun::ForceComplex);
     run.setTabSize(!collapseWhiteSpace, text->style()->tabSize());
     run.setXPos(xPos);
-    return font.width(run, fallbackFonts, nullptr);
+    return font.width(run, fallbackFonts, glyphBounds);
 }
 
 inline bool BreakingContext::handleText(WordMeasurements& wordMeasurements, bool& hyphenated)
@@ -643,9 +639,9 @@ inline bool BreakingContext::handleText(WordMeasurements& wordMeasurements, bool
 
             float additionalTempWidth;
             if (wordTrailingSpaceWidth && c == spaceCharacter)
-                additionalTempWidth = textWidth(layoutText, lastSpace, m_current.offset() + 1 - lastSpace, font, m_width.currentWidth(), m_collapseWhiteSpace, &wordMeasurement.fallbackFonts) - wordTrailingSpaceWidth;
+                additionalTempWidth = textWidth(layoutText, lastSpace, m_current.offset() + 1 - lastSpace, font, m_width.currentWidth(), m_collapseWhiteSpace, &wordMeasurement.fallbackFonts, &wordMeasurement.glyphBounds) - wordTrailingSpaceWidth;
             else
-                additionalTempWidth = textWidth(layoutText, lastSpace, m_current.offset() - lastSpace, font, m_width.currentWidth(), m_collapseWhiteSpace, &wordMeasurement.fallbackFonts);
+                additionalTempWidth = textWidth(layoutText, lastSpace, m_current.offset() - lastSpace, font, m_width.currentWidth(), m_collapseWhiteSpace, &wordMeasurement.fallbackFonts, &wordMeasurement.glyphBounds);
 
             wordMeasurement.width = additionalTempWidth + wordSpacingForWordMeasurement;
             additionalTempWidth += lastSpaceWordSpacing;
@@ -669,7 +665,7 @@ inline bool BreakingContext::handleText(WordMeasurements& wordMeasurements, bool
                 // as candidate width for this line.
                 bool lineWasTooWide = false;
                 if (m_width.fitsOnLine() && m_currentCharacterIsSpace && m_currentStyle->breakOnlyAfterWhiteSpace() && !midWordBreak) {
-                    float charWidth = textWidth(layoutText, m_current.offset(), 1, font, m_width.currentWidth(), m_collapseWhiteSpace, &wordMeasurement.fallbackFonts) + (applyWordSpacing ? wordSpacing : 0);
+                    float charWidth = textWidth(layoutText, m_current.offset(), 1, font, m_width.currentWidth(), m_collapseWhiteSpace, &wordMeasurement.fallbackFonts, &wordMeasurement.glyphBounds) + (applyWordSpacing ? wordSpacing : 0);
                     // Check if line is too big even without the extra space
                     // at the end of the line. If it is not, do nothing.
                     // If the line needs the extra whitespace to be too long,
@@ -805,7 +801,7 @@ inline bool BreakingContext::handleText(WordMeasurements& wordMeasurements, bool
     wordMeasurement.layoutText = layoutText;
 
     // IMPORTANT: current.m_pos is > length here!
-    float additionalTempWidth = m_ignoringSpaces ? 0 : textWidth(layoutText, lastSpace, m_current.offset() - lastSpace, font, m_width.currentWidth(), m_collapseWhiteSpace, &wordMeasurement.fallbackFonts);
+    float additionalTempWidth = m_ignoringSpaces ? 0 : textWidth(layoutText, lastSpace, m_current.offset() - lastSpace, font, m_width.currentWidth(), m_collapseWhiteSpace, &wordMeasurement.fallbackFonts, &wordMeasurement.glyphBounds);
     wordMeasurement.startOffset = lastSpace;
     wordMeasurement.endOffset = m_current.offset();
     wordMeasurement.width = m_ignoringSpaces ? 0 : additionalTempWidth + wordSpacingForWordMeasurement;