[bedrock] Eliminate BrowserWindowInterface deps from BrowserList

This CL removes BrowserWindowInterface deps from BrowserList as
mixing BrowserCollection and BrowserList logic can result in
confusing and incorrect behavior.

After this CL BrowserList and its associated tests will depend
only on BrowserList, which prevents conflict. Both BrowserList
and its associated tests will be shortly. removed.

Bug: 441824481
Change-Id: Ia3eb807121901b7562ca4b89f7ca4d3f45296576
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7604383
Commit-Queue: Tom Lukaszewicz <tluk@chromium.org>
Reviewed-by: Qikai Zhong <qikaizhong@microsoft.com>
Cr-Commit-Position: refs/heads/main@{#1590413}