DocExtraTest#testDocExtraLoadingFromURLAnchor is flickering

element [historycontent] not found

com.thoughtworks.selenium.Wait$WaitTimedOutException: element [historycontent] not found
	at com.thoughtworks.selenium.Wait.wait(Wait.java:98)
	at com.thoughtworks.selenium.Wait.wait(Wait.java:63)
	at org.xwiki.test.selenium.framework.AbstractXWikiTestCase.waitForElement(AbstractXWikiTestCase.java:446)
	at org.xwiki.test.selenium.DocExtraTest.waitForDocExtraPaneActive(DocExtraTest.java:163)
	at org.xwiki.test.selenium.DocExtraTest.testDocExtraLoadingFromURLAnchor(DocExtraTest.java:115)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:497)
	at junit.framework.TestCase.runTest(TestCase.java:176)
	at org.xwiki.test.selenium.framework.AbstractXWikiTestCase.runBare(AbstractXWikiTestCase.java:129)
	at junit.framework.TestResult$1.protect(TestResult.java:122)
	at junit.framework.TestResult.runProtected(TestResult.java:142)
	at junit.framework.TestResult.run(TestResult.java:125)
	at junit.framework.TestCase.run(TestCase.java:129)
	at junit.framework.TestSuite.runTest(TestSuite.java:252)
	at org.xwiki.test.selenium.framework.XWikiTestSuite.runTest(XWikiTestSuite.java:65)
	at junit.framework.TestSuite.run(TestSuite.java:247)
	at junit.framework.TestSuite.runTest(TestSuite.java:252)
	at junit.framework.TestSuite.run(TestSuite.java:247)
	at junit.extensions.TestDecorator.basicRun(TestDecorator.java:23)
	at junit.extensions.TestSetup$1.protect(TestSetup.java:23)
	at junit.framework.TestResult.runProtected(TestResult.java:142)
	at junit.extensions.TestSetup.run(TestSetup.java:27)
	at junit.extensions.TestDecorator.basicRun(TestDecorator.java:23)
	at junit.extensions.TestSetup$1.protect(TestSetup.java:23)
	at junit.framework.TestResult.runProtected(TestResult.java:142)
	at junit.extensions.TestSetup.run(TestSetup.java:27)
	at org.junit.internal.runners.JUnit38ClassRunner.run(JUnit38ClassRunner.java:86)
	at org.apache.maven.surefire.junit4.JUnit4Provider.execute(JUnit4Provider.java:367)
	at org.apache.maven.surefire.junit4.JUnit4Provider.executeWithRerun(JUnit4Provider.java:274)
	at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:238)
	at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:161)
	at org.apache.maven.surefire.booter.ForkedBooter.invokeProviderInSameClassLoader(ForkedBooter.java:290)
	at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:242)
	at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:121)