Revert of Get rid of computeVisibleSelectionInDOMTreeDeprecated() in InputMethodController

Revert of Get rid of computeVisibleSelectionInDOMTreeDeprecated() in InputMethodController (patchset #5 id:80001 of https://codereview.chromium.org/2782413002/ )

Reason for revert:
This caused large memory regressions. See http://crbug.com/711366 for details.

BUG=711366
Original issue's description:
> Get rid of computeVisibleSelectionInDOMTreeDeprecated() in InputMethodController::textInputType() and textInputInfo()
> 
> This patch gets rid of |computeVisibleSelectionInDOMTreeDeprecated()| by replacing
> it with |rootEditableElementOf()| with non-canonicalize position from
> |textInputInfo()| and |textInputType()| of |InputMethodController| for improving
> code health.
> 
> Node: Because of selection can't cross editing boundary, root editable element for
> non-canonicalized position and canonicalized position are same.
> 
> This patch is intentionally not change all call sites of |rootEditableElement()|
> in |InputMethodController| to merge this patch as workaround of [1].
> 
> [1] http://crbug.com/704763 Opacity animation consuming main thread resources
> 
> BUG=698633, 704763
> TEST=n/a; no behavior changes
> 
> Review-Url: https://codereview.chromium.org/2782413002
> Cr-Original-Commit-Position: refs/heads/master@{#460705}
> Committed: https://chromium.googlesource.com/chromium/src/+/9744d5bffb3fbdf761455b355ebc4faa757d1aaf
> Review-Url: https://codereview.chromium.org/2782413002
> Cr-Commit-Position: refs/heads/master@{#463575}
> Committed: https://chromium.googlesource.com/chromium/src/+/e14aacd2baf5cf9c4a5e457384e0b0f73c0163c4

TBR=tkent@chromium.org,xiaochengh@chromium.org,yoichio@chromium.org,yosin@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=698633, 704763

[sullivan, 2017-04-26 13:09:36]

The CQ bit was checked by sullivan@chromium.org

[sullivan, 2017-04-26 13:09:37]

Created Revert of Get rid of computeVisibleSelectionInDOMTreeDeprecated() in
InputMethodController

[commit-bot: I haz the power, 2017-04-26 13:09:57]

CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-04-26 13:12:42]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-04-26 13:12:44]

Try jobs failed on following builders:
  linux_chromium_chromeos_ozone_rel_ng on master.tryserver.chromium.linux
(JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[yosin_UTC9, 2017-04-27 04:34:42]

I created patch[1] for identical of this revert patch.

[1] http://crrev.com/2849453002: Add redundant update layout in
InputMethodController to solve memory regresssion