Disable WebViewTest.Dialog_TestConfirmDialogDefaultGCCancel.

BUG=314809
R=fsamuel@chromium.org

Review URL: https://codereview.chromium.org/59133004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@232993 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 232993