Remove some unneeded includes of svg_element.h

Cq-Include-Trybots: luci.chromium.try:linux_layout_tests_slimming_paint_v2;master.tryserver.blink:linux_trusty_blink_rel
Change-Id: I989622cb82e8135d387f5807723eaf0704e2bbb3
Reviewed-on: https://chromium-review.googlesource.com/1188306
Reviewed-by: Philip Rogers <pdr@chromium.org>
Commit-Queue: Fredrik Söderquist <fs@opera.com>
Cr-Commit-Position: refs/heads/master@{#585842}
8 files changed