Adjust SVGImageElement::InsertedInto to match HTMLImageElement

This does the same edit to SVGImageElement::InsertedInto as
https://chromium-review.googlesource.com/1141121 did to HTMLImageElement.

Bug: 864306
Cq-Include-Trybots: luci.chromium.try:linux_layout_tests_slimming_paint_v2;master.tryserver.blink:linux_trusty_blink_rel
Change-Id: I74696c16c27eba363e4965d996f3ae688ef27c91
Reviewed-on: https://chromium-review.googlesource.com/1254265
Reviewed-by: vmpstr <vmpstr@chromium.org>
Commit-Queue: Fredrik Söderquist <fs@opera.com>
Cr-Commit-Position: refs/heads/master@{#595507}
2 files changed