Fix bug where tab hover card keyboard navigation did not work on Mac.

When keyboard navigating the tab strip on Mac pane_has_focus is not set to true so key events were hiding the tab hover cards when they shouldnt have been. This change instead ignores hiding cards on when updating the hover card if the tab strip or one of its children (excluding the new tab button) has focus.

Bug: 910739, 974896
Change-Id: I306543684f448fa3e4ceac0f346a5b833f334b7e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1650213
Commit-Queue: Caroline Rising <corising@chromium.org>
Reviewed-by: Dana Fried <dfried@chromium.org>
Cr-Commit-Position: refs/heads/master@{#669897}
8 files changed