Remove TabModelObserver usage from TabStripController.

The last method from didChangeTab which was used to update tab title
and update the loading spinner.
Instead of using TabModelObserver didChangeTab, use WebStateObserver to
monitor all webStates and use didStartLoading/didStopLoading to update
the spinner. Also use WebStateObserver didChangeTitle to update the
tabview title.

Bug: 911350
Change-Id: Ie1b0bfc77d7dca39e27e6efb6e8478aaaf9e9a4d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1630628
Commit-Queue: Mohammad Refaat <[email protected]>
Reviewed-by: Mark Cogan <[email protected]>
Cr-Commit-Position: refs/heads/master@{#664280}
1 file changed