Fix incorrect handling of small non-percentage value for 'startOffset' on <textPath>

third_party/WebKit/Source/core/layout/svg/LayoutSVGTextPath.cpp

 /*
  * Copyright (C) 2007 Nikolas Zimmermann <zimmermann@kde.org>
  *
  * 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.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 41 matching lines @@
     // supplemental transformation relative to the current user coordinate system for
     // the current 'text' element, including any adjustments to the current user coordinate
     // system due to a possible transform attribute on the current 'text' element.
     // http://www.w3.org/TR/SVG/text.html#TextPathElement
     pathData.transform(pathElement.calculateAnimatedLocalTransform());
     return pathData;
 }
 
 float LayoutSVGTextPath::startOffset() const
 {
-    return toSVGTextPathElement(node())->startOffset()->currentValue()->valueAsPercentage();
+    float textPathStartOffset = toSVGTextPathElement(node())->startOffset()->currentValue()->valueAsPercentage();
+    if (isPercentageForStartOffset()) {
+        if (textPathStartOffset > 0 && textPathStartOffset <= 1)

[fs, 2016/01/28 14:00:20]

This condition does not do anything useful. The spec does not place this
restriction on a percentage startOffset AFAIK.

+            textPathStartOffset *= layoutPath().length();

[fs, 2016/01/28 14:00:20]

We don't want to call layoutPath() again here - and Path::length() is a fairly
expensive operation - just pass a |pathLength| as an argument to this function
instead.

+    }
+    return textPathStartOffset;
+}
+
+bool LayoutSVGTextPath::isPercentageForStartOffset() const

[fs, 2016/01/28 14:00:20]

Don't need this method - just inline this check in the one place where it's
needed.

+{
+    return toSVGTextPathElement(node())->startOffset()->currentValue()->isPercentage();
 }
 
 } // namespace blink