Simplify HTMLImageElement::canStartSelection()

It originally always return true, and got its current behavior as part
of "Shadow DOM for img element" which was reverted:
http://trac.webkit.org/changeset/122824
http://trac.webkit.org/changeset/125397
http://trac.webkit.org/changeset/140097

What is left looks odd in isolation, so revert it for now.

Review URL: https://codereview.chromium.org/858533002

git-svn-id: svn://svn.chromium.org/blink/trunk@188603 bbb929c8-8fbe-4397-9dbb-9b2b20218538
2 files changed
tree: dfc408a960240f19969adc960dffbc3b49876d1c
  1. third_party/