Tests sidebars in WebInspector extensions API

Started extension.
Running tests...
RUNNING TEST: extension_testSidebarPageReplacedWithObject
Got onShown(), frame defined
Got onShown(), frame not defined
RUNNING TEST: extension_testSidebarSetExpression
log: Extension server error: Inspector protocol error: Object has too long reference chain(must not be longer than 1000)
Sidebar content: titlef0: "expression"f1: undefinedf2: nullf3: Objectf4: Array[0]f5: Array[3]f6: Objectf7: 42f8: Locationf9: HTMLCollection[2]f10: function () {}f11: "foo"__proto__: Object
RUNNING TEST: extension_testSidebarSetObject
Watch sidebar created, callback arguments dump follows:
{
    0 : {
        onHidden : {
            addListener : <function>
            removeListener : <function>
        }
        onShown : {
            addListener : <function>
            removeListener : <function>
        }
        setExpression : <function>
        setHeight : <function>
        setObject : <function>
        setPage : <function>
    }
}
Sidebar content: f0: "object"f1: undefinedf2: nullf3: {}f4: []f5: [aa, bb, cc]f6: {f60:42, f61:foo, f62:[]}f7: 42
RUNNING TEST: extension_testSidebarSetPage
Sidebar created
{
    onHidden : {
        addListener : <function>
        removeListener : <function>
    }
    onShown : {
        addListener : <function>
        removeListener : <function>
    }
    setExpression : <function>
    setHeight : <function>
    setObject : <function>
    setPage : <function>
}
All tests done.