Specify session history navigation

[jgraham]

We should have commands for moving around in history.

Currently WebDriver has forward and back commands that correspond to tranversing the hsitory by a delta in the HTML spec. This is straightforward to specify. CDP takes a different approach; it allows getting a list of session history entries and navigating to an entry by id. Probably that's widely implementable because it corresponds to browser features like a drop down on the back button showing the full history. The question is whether the additional flexibility has use cases that merit the additional complexity.

[jgraham]

Per the meeting discussion we should go ahead and specify a mechaism to traverse history by a delta and not worry about full access to the session history for now.

[OrKoN]

There is an additional use case that was mentioned to us by WPT test authors. In WPT there is a need to test the behavior of the back/forward buttons that takes the history manipulation prevention into account https://chromium.googlesource.com/chromium/src/+/refs/heads/lkgr/docs/history_manipulation_intervention.md Currently, we can only invoke the behavior described by the HTML spec and we omit the behavior that would potentially affect the end user.