Fixed positioning of tooltips in multi monitor setups.

If window is positioned on right monitor in multimonitor setup
tooltips for items to the left of Chromium window appear on left screen.
This is because screen on which to display the tooltip is calculated from
DIP coordinates.

BUG=

Review URL: https://codereview.chromium.org/225403022

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@272218 0039d316-1c4b-4281-b951-d872f2087c98
4 files changed