temporary workaround for alien SVGElement in Chrome

When using this fix, the call site must ensure availability of
getComputedStyle, and pass in a compatible SVGElement instance.

for background, see:
alafr#47 (comment)

source.js

@@ -2186,7 +2186,7 @@ var SVGtoPDF = function(doc, svg, x, y, options) {
         viewportWidth = (options.width || doc.page.width) / pxToPt,
         viewportHeight = (options.height || doc.page.height) / pxToPt,
         preserveAspectRatio = options.preserveAspectRatio || null, // default to null so that the attr can override if not passed
-        useCSS = options.useCSS && typeof SVGElement !== 'undefined' && svg instanceof SVGElement && typeof getComputedStyle === 'function',
+        useCSS = options.useCSS,
         warningCallback = options.warningCallback,
         fontCallback = options.fontCallback,
         imageCallback = options.imageCallback,