Return used width/height for SVG <image>, <rect> and <foreignObject>

Per we should return the
"used value" for 'width' and 'height' on these elements [1].
This behavior was clarified in SVGWG GitHub issue #349 [2].

[1] And also on <svg>, but we don't support those properties there yet.
    Tests added for that case too though.

Bug: 772707
Change-Id: Ic7b6b148883d4380daadb41b62bddd02da55e1af
Reviewed-by: Philip Rogers <>
Commit-Queue: Fredrik Söderquist <>
Cr-Commit-Position: refs/heads/master@{#616343}
10 files changed