Created attachment 49642 [details] Implements my idea, though scrolls per-line and not per-resource The Timeline in the Resources Pane should be vertically scrollable with the keyboard. We could make it scroll by one resource-width per scroll.
Closing as invalid, as this bug pertains to the old inspector UI and/or its tests. Please file a new bug (https://www.webkit.org/new-inspector-bug) if the bug/feature/issue is still relevant to WebKit trunk.