GitLab

This CL adds a virtual keyboard icon when a11y VK is enabled. Click or tap on
the icon will force the VK to show and lock.

BUG=346695

Review URL: https://codereview.chromium.org/177123016

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@255307 0039d316-1c4b-4281-b951-d872f2087c98