spellcheck-editable-on-focus.html does not tests all elements

spellcheck-editable-on-focus.html does not test all elements

This tests misspellings on editable elements (div, text area, input).
However, after r161840 only first one is being tested.

Additionally, rename setFocusOnEditableElements() to triggerSpellingForEditables()
to better describe what it does.

BUG=

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=162124

[grzegorz, 2013-11-15 13:29:06]

I introduced it by mistake at https://codereview.chromium.org/25507002/. Sorry
for that :/

[tony, 2013-11-15 17:01:59]

LGTM

[commit-bot: I haz the power, 2013-11-15 17:02:36]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/g.czajkowski@samsung.com/74003003/1

[commit-bot: I haz the power, 2013-11-15 18:22:03]

Change committed as 162124