Fix Wrong Offset

Set content offset using fill_into_edit's length and not the length of the originally typed term.

BUG=82994
TEST=Added unit test. Manual test: 1) Delete the 'History Provider Cache' file, 2) Start Chrome, 3) Type 'about:flags' into omnibox and <ret>, 4) Type 'about:flags/' or 'about:flags@' into omnibox. There should no longer be an assert at this point.
Review URL: http://codereview.chromium.org/7004042

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@86171 0039d316-1c4b-4281-b951-d872f2087c98
2 files changed