* refactor: use AddChildView(std::unique_ptr<View>) in OpaqueFrameView::CreateButton()
Xref: https://issues.chromium.org/issues/40485510
* refactor: use AddChildView(std::unique_ptr<View>) in MenuBar::RebuildChildren()
* refactor: use AddChildView(std::unique_ptr<View>) for ClientFrameViewLinux labels
* refactor: use AddChildView(std::unique_ptr<View>) for ClientFrameViewLinux buttons
* refactor: use AddChildView(std::unique_ptr<View>) in AutofillPopupView
* refactor: use AddChildViewRaw() to flag the edge cases that we still need to fix
* chore: use west coast const for consistency
85dce12be3