Fix crash bug where we try to access SidePanelToolbarContainer for windows where it doesn't exist.

Some windows (like dev tools in a separate window) don't have the
SidePanelToolbarContainer, when this is the case we shouldn't try to
access it to update the pin state.

Bug: 1448832
Change-Id: I2e79e197e20c6e61e98cfa4485e092d8a808d7ba
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4567707


Commit-Queue: Caroline Rising <corising@chromium.org>
Code-Coverage: Findit <findit-for-me@appspot.gserviceaccount.com>
Reviewed-by: Michael Crouse <mcrouse@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1149239}