Fix cursor positioning regression from r201136.  GetCursorPos() shouldn't assume
vertically-centered text.

BUG=242801
TEST=Arrow through the omnibox in 200% mode and ensure the cursor does not appear vertically too low
R=asvitkine@chromium.org, msw@chromium.org

Review URL: https://codereview.chromium.org/15746013

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@201944 0039d316-1c4b-4281-b951-d872f2087c98
9 files changed