Get rid of a unused parameter from Editor::notifyComponentsOnChangedSelection()

This patch gets rid of a unused parameter from
|Editor::notifyComponentsOnChangedSelection()| to simplify source code for
improving code health.

BUG=n/a
TEST=n/a; no behavior changes

Review-Url: https://codereview.chromium.org/2018413003
Cr-Commit-Position: refs/heads/master@{#396797}
2 files changed