I am seeing the following warning when opening the Messages panel

Warning: validateDOMNesting(...): <tr> cannot appear as a child of <table>. Add a <tbody> to your code to match the DOM tree generated by the browser.
    in tr (created by FrameListContent)
    in table (created by FrameListContent)
    in div (created by FrameListContent)
    in FrameListContent
    in VisibilityHandler
    in Unknown (created by Connect(Component))
    in Connect(Component) (created by WebSocketsPanel)
    in div (created by SplitBox)
    in div (created by SplitBox)
    in SplitBox (created by WebSocketsPanel)
    in div (created by WebSocketsPanel)
    in WebSocketsPanel
    in VisibilityHandler
    in Unknown (created by Connect(Component))
    in Connect(Component) (created by TabboxPanel)
    in div (created by Panel)
    in Panel (created by TabboxPanel)
    in div (created by Tabs)
    in div (created by Tabs)
    in div (created by Tabs)
    in Tabs (created by Sidebar)
    in Sidebar (created by Tabbar)
    in div (created by Tabbar)
    in Tabbar (created by TabboxPanel)
    in TabboxPanel (created by NetworkDetailsPanel)
    in div (created by NetworkDetailsPanel)
    in NetworkDetailsPanel
    in VisibilityHandler
    in Unknown (created by Connect(Component))
    in Connect(Component) (created by MonitorPanel)
    in div (created by SplitBox)
    in div (created by SplitBox)
    in SplitBox (created by MonitorPanel)
    in div (created by MonitorPanel)
    in MonitorPanel
    in VisibilityHandler
    in Unknown (created by Connect(Component))
    in Connect(Component) (created by App)
    in div (created by DropHarHandler)
    in DropHarHandler (created by App)
    in div (created by App)
    in App
    in VisibilityHandler
    in Unknown (created by Connect(Component))
    in Connect(Component)
    in Provider

@Heng Yeow: can you please look at this, thanks.
Honza

Fix warnings in Browser Toolbox.

https://hg.mozilla.org/mozilla-central/rev/b800ffcad849