Revert of Makes sure the keyboard typing isn't blocked when InputMethod::OnFocus() is not correctly called. (patchset #21 id:400001 of https://codereview.chromium.org/1566083002/ )

Reason for revert:
Very high crash rate.

BUG=579910

Original issue's description:
> Makes sure the keyboard typing isn't blocked when InputMethod::OnFocus() is not correctly called.
>
> BUG=569339,505231
> TEST=None
>
> Committed: https://crrev.com/d6b55d458f5d3ebeba2826520f14b4bf0e571396
> Cr-Commit-Position: refs/heads/master@{#370340}

TBR=yukawa@chromium.org,sky@chromium.org,eroman@chromium.org,shuchen@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=569339,505231

Review URL: https://codereview.chromium.org/1615073005

Cr-Commit-Position: refs/heads/master@{#370828}
17 files changed