Store glyph bounds in WordMeasurement to avoid slow path width calc

Source/core/layout/line/BreakingContextInlineHeaders.h

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2003, 2004, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All right reserved.
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) 2013 Adobe Systems Incorporated.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 491 matching lines @@
     return font.width(constructTextRun(layoutText, font,
         style.hyphenString().string(), style, style.direction()));
 }
 
 ALWAYS_INLINE TextDirection textDirectionFromUnicode(WTF::Unicode::Direction direction)
 {
     return direction == WTF::Unicode::RightToLeft
         || 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)
 {
     if (!m_current.offset())
         m_appliedStartWidth = false;
 
     LayoutText* layoutText = toLayoutText(m_current.object());
 
     bool isSVGText = layoutText->isSVGInlineText();
@@ skipping 100 matching lines @@
 
             wordMeasurements.grow(wordMeasurements.size() + 1);
             WordMeasurement& wordMeasurement = wordMeasurements.last();
 
             wordMeasurement.layoutText = layoutText;
             wordMeasurement.endOffset = m_current.offset();
             wordMeasurement.startOffset = lastSpace;
 
             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;
             m_width.addUncommittedWidth(additionalTempWidth);
 
             if (m_collapseWhiteSpace && previousCharacterIsSpace && m_currentCharacterIsSpace && additionalTempWidth)
                 m_width.setTrailingWhitespaceWidth(additionalTempWidth);
 
             if (!m_appliedStartWidth) {
                 m_width.addUncommittedWidth(inlineLogicalWidth(m_current.object(), true, false).toFloat());
                 m_appliedStartWidth = true;
             }
 
             applyWordSpacing = wordSpacing && m_currentCharacterIsSpace;
 
             if (!m_width.committedWidth() && m_autoWrap && !m_width.fitsOnLine())
                 m_width.fitBelowFloats(m_lineInfo.isFirstLine());
 
             if (m_autoWrap || breakWords) {
                 // If we break only after white-space, consider the current character
                 // 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,
                     // then move the line break to the space and skip all
                     // additional whitespace.
                     if (!m_width.fitsOnLine(charWidth)) {
                         lineWasTooWide = true;
                         m_lineBreak.moveTo(m_current.object(), m_current.offset(), m_current.nextBreakablePosition());
                         skipTrailingWhitespace(m_lineBreak, m_lineInfo);
                     }
@@ skipping 115 matching lines @@
         nextCharacter(c, lastCharacter, secondToLastCharacter);
     }
 
     m_layoutTextInfo.m_lineBreakIterator.setPriorContext(lastCharacter, secondToLastCharacter);
 
     wordMeasurements.grow(wordMeasurements.size() + 1);
     WordMeasurement& wordMeasurement = wordMeasurements.last();
     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;
     additionalTempWidth += lastSpaceWordSpacing;
 
     LayoutUnit inlineLogicalTempWidth = inlineLogicalWidth(m_current.object(), !m_appliedStartWidth, m_includeEndWidth);
     m_width.addUncommittedWidth(additionalTempWidth + inlineLogicalTempWidth);
 
     if (m_collapseWhiteSpace && m_currentCharacterIsSpace && additionalTempWidth)
         m_width.setTrailingWhitespaceWidth(additionalTempWidth + inlineLogicalTempWidth);
@@ skipping 83 matching lines @@
 
     if (style.textIndentType() == TextIndentHanging)
         shouldIndentText = shouldIndentText == IndentText ? DoNotIndentText : IndentText;
 
     return shouldIndentText;
 }
 
 }
 
 #endif // BreakingContextInlineHeaders_h