Rework SVG sizing

Source/core/css/svg.css

 /*
  * The default style sheet used to render SVG.
  *
  * Copyright (C) 2005, 2006 Apple Computer, Inc.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 29 matching lines @@
     the initial clipping path is set according to the clipping rules as defined in [CSS2-overflow].
 
     Opera/Firefox & WebKit agreed on NOT setting "overflow: hidden" for the outermost svg element - SVG 1.1 Errata
     contains these changes as well as all future SVG specifications: see http://lists.w3.org/Archives/Public/public-svg-wg/2008JulSep/0347.html
 */
 
 svg:not(:root), symbol, image, marker, pattern, foreignObject {
     overflow: hidden
 }
 
+svg:root {

[eseidel, 2014/04/18 16:12:49]

I'm surprised we didn't already ahve this.  Or maybe SVGSVGElement has magical
sizing rules?  I remember fighting with this for a loooong time years ago.

[davve, 2014/04/18 17:24:32]

WebKit had something similar until
https://bugs.webkit.org/show_bug.cgi?id=76447. It was partly based on a
misunderstanding though, as I've been told from old-timers. The 100% default
values was never intended to be included in the viewport calculation. Making
width/height presentation attributes is a compromise that allows percentage
values to be part of the viewport calculation, but the default value should not
be 100%.

https://docs.google.com/presentation/d/1POUiroOBbLmXYlQKf0pIR8zVkHWH9jRVN-w8A...

is the link to the slides I presented and posted to blink-dev a couple of weeks
ago.

+    width: 100%;
+    height: 100%
+}
+
 text, foreignObject {
     display: block
 }
 
 text {
    white-space: nowrap
 }
 
 tspan, textPath {
    white-space: inherit
 }
 
 /* states */
 
 :focus {
     outline: auto 5px -webkit-focus-ring-color
 }
 
 /* CSS transform specification: "transform-origin 0 0 for SVG elements without associated CSS layout box, 50% 50% for all other elements". */
  
 * {
     -webkit-transform-origin: 0 0;
 }
 
 html|* > svg {
     -webkit-transform-origin: 50% 50%;
 }