A recent CL to add reader mode for clank started triggering this codepath on
load and was interfering with how the virtual keyboard handles programmatic
focus() calls. This rogue UGI seems to have been added to get pyauto tests to
pass, we should be able to only set this for tests.

This is part 1 of 3, will be followed by:
https://codereview.chromium.org/518583003/

BUG=408426,407643

Review URL: https://codereview.chromium.org/516753002

git-svn-id: svn://svn.chromium.org/blink/trunk@181075 bbb929c8-8fbe-4397-9dbb-9b2b20218538