Fixes possible crash in TableView
The sequence leading to the crash is:
. Enable sorting.
. Have more than one selected row.
. Remove one of the selected rows. The removed row must also contain
the anchor.
. Focus the table.
The crash happened because we tried to get the view index for -1.
In general the anchor shouldn't be -1 if there is at least one item in
the selection. The only place anchor could be -1 and there is a
selection is during removal. This patch fixes that.
BUG=480296
TEST=covered by test now.
R=sadrul@chromium.org
Review URL: https://codereview.chromium.org/
1129233006
Cr-Commit-Position: refs/heads/master@{#329853}