Include glyph overflow in SVG text bounding boxes

third_party/WebKit/Source/core/layout/line/GlyphOverflow.h

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2006, 2007, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Holger Hans Peter Freyther
  *
  * 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
@@ skipping 28 matching lines @@
         , top(0)
         , bottom(0)
     {
     }
 
     bool isZero() const
     {
         return !left && !right && !top && !bottom;
     }
 
+    // These helper functions are exposed to share logic with SVG which computes overflow
+    // in floating point (see: SVGTextLayoutEngine).
+    static float topOverflow(const FloatRect& bounds, float ascent)
+    {
+        return std::max(0.0f, -bounds.y() - ascent);
+    }
+    static float bottomOverflow(const FloatRect& bounds, float descent)
+    {
+        return std::max(0.0f, bounds.maxY() - descent);
+    }
+    static float leftOverflow(const FloatRect& bounds)
+    {
+        return std::max(0.0f, -bounds.x());
+    }
+    static float rightOverflow(const FloatRect& bounds, float textWidth)
+    {
+        return std::max(0.0f, bounds.maxX() - textWidth);
+    }
+
     void setFromBounds(const FloatRect& bounds, float ascent, float descent, float textWidth)
     {
-        top = ceilf(std::max(0.0f, -bounds.y() - ascent));
-        bottom = ceilf(std::max(0.0f, bounds.maxY() - descent));
-        left = ceilf(std::max(0.0f, -bounds.x()));
-        right = ceilf(std::max(0.0f, bounds.maxX() - textWidth));
+        top = ceilf(topOverflow(bounds, ascent));
+        bottom = ceilf(bottomOverflow(bounds, descent));
+        left = ceilf(leftOverflow(bounds));
+        right = ceilf(rightOverflow(bounds, textWidth));
     }
 
     // Top and bottom are the amounts of glyph overflows exceeding the font metrics' ascent and descent, respectively.
     // Left and right are the amounts of glyph overflows exceeding the left and right edge of normal layout boundary, respectively.
     // All fields are in absolute number of pixels rounded up to the nearest integer.
     int left;
     int right;
     int top;
     int bottom;
 };
 
 } // namespace blink
 
 #endif // GlyphOverflow_h