Adds system keys to the virtual keyboard. Note the keys as yet do not call the correct function keys. This will be done in a later patch.


BUG=297103

Review URL: https://codereview.chromium.org/27056002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@228742 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 228742