Font metrics, version 1

Source/platform/fonts/FontFastPath.cpp

Index: Source/platform/fonts/FontFastPath.cpp
diff --git a/Source/platform/fonts/FontFastPath.cpp b/Source/platform/fonts/FontFastPath.cpp
index 93e9015e08b1d050895e21ce0ccbc98aa6a53925..68ba4d5bd25ce40e831e77e18d3c94e42109f4f7 100644
--- a/Source/platform/fonts/FontFastPath.cpp
+++ b/Source/platform/fonts/FontFastPath.cpp
@@ -550,10 +550,10 @@ float Font::floatWidthForSimpleText(const TextRun& run, HashSet<const SimpleFont
     return it.m_runWidthSoFar;
 }
 
-FloatRect Font::selectionRectForSimpleText(const TextRun& run, const FloatPoint& point, int h, int from, int to) const
+FloatRect Font::selectionRectForSimpleText(const TextRun& run, const FloatPoint& point, int h, int from, int to, bool accountForGlyphBounds) const
 {
     GlyphBuffer glyphBuffer;
-    WidthIterator it(this, run);
+    WidthIterator it(this, run, 0, accountForGlyphBounds);
     it.advance(from, &glyphBuffer);
     float beforeWidth = it.m_runWidthSoFar;
     it.advance(to, &glyphBuffer);
@@ -567,13 +567,15 @@ FloatRect Font::selectionRectForSimpleText(const TextRun& run, const FloatPoint&
         it.advance(run.length(), &glyphBuffer);
         float totalWidth = it.m_runWidthSoFar;
         float pixelAlignedX = floorf(point.x() + totalWidth - afterWidth + LayoutUnit::epsilon());
-        return FloatRect(pixelAlignedX, point.y(),
-            roundf(point.x() + totalWidth - beforeWidth) - pixelAlignedX, h);
+        return FloatRect(pixelAlignedX, point.y() + accountForGlyphBounds ? it.minGlyphBoundingBoxY() : 0,
+            roundf(point.x() + totalWidth - beforeWidth) - pixelAlignedX,
+            accountForGlyphBounds ? it.maxGlyphBoundingBoxY() - it.minGlyphBoundingBoxY() : h);
     }
 
     float pixelAlignedX = floorf(point.x() + beforeWidth + LayoutUnit::epsilon());
-    return FloatRect(pixelAlignedX, point.y(),
-        roundf(point.x() + afterWidth) - pixelAlignedX, h);
+    return FloatRect(pixelAlignedX, point.y() + accountForGlyphBounds ? it.minGlyphBoundingBoxY() : 0,
+        roundf(point.x() + afterWidth) - pixelAlignedX,
+        accountForGlyphBounds ? it.maxGlyphBoundingBoxY() - it.minGlyphBoundingBoxY() : h);
 }
 
 int Font::offsetForPositionForSimpleText(const TextRun& run, float x, bool includePartialGlyphs) const