| # Visibility Timer | |
| `VisibilityTimerTabHelper` is a `WebContentsObserver` that executes a task after | |
| the `WebContents` has been continuously visible for a set amount of time. If the | |
| tab becomes hidden before the timer fires, the timer is reset. This is useful | |
| for deferring non-critical actions until a user explicitly keeps a tab visible | |
| for a given duration. |