Templatize FrameSelection::setNonDirectionalSelectionIfNeede function

Templatize FrameSelection::setNonDirectionalSelectionIfNeede function

This patch introduces a template function |setNonDirectionalSelectionIfNeedeAlgorithm<Strategy>|
to makes |FrameSelection::setNonDirectionalSelectionIfNeede()| function to work
both on DOM tree and composed tree with introducing member functions to strategy
class |VisibleSelection::InDOMTree|.

This patch is result of collaboration work with hajimehoshi@chromium.org
for selection of web components. After this patch, we are going to
implement another strategies for the composed tree. We've already
prepared that at http://crrev.com/1106433002.

BUG=275851
TEST=n/a; No behavior changes.

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=197326

[yosin_UTC9, 2015-06-18 05:24:32]

Patchset #1 (id:1) has been deleted

[yosin_UTC9, 2015-06-18 06:17:51]

yosin@chromium.org changed reviewers:
+ yoichio@chromium.org

[yosin_UTC9, 2015-06-18 06:17:51]

PTAL

[yosin_UTC9, 2015-06-18 07:28:28]

yosin@chromium.org changed reviewers:
+ tkent@chromium.org
- yoichio@chromium.org

[yosin_UTC9, 2015-06-18 07:28:29]

PTAL

[tkent, 2015-06-18 07:41:46]

The CQ bit was checked by tkent@chromium.org

[tkent, 2015-06-18 07:41:46]

lgtm

[commit-bot: I haz the power, 2015-06-18 07:42:07]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1177173007/20001

[commit-bot: I haz the power, 2015-06-18 07:46:36]

Committed patchset #1 (id:20001) as
https://src.chromium.org/viewvc/blink?view=rev&revision=197326