Mitigate issues with AccordionClipsContentTest on IE8.

Change-Id: I7a617f2d1e9d9b24390ea3dded5b68d5f29eb9cb

uitest/src/com/vaadin/tests/components/accordion/AccordionClipsContentTest.java

@@ -15,10 +15,9 @@
  */
 package com.vaadin.tests.components.accordion;
 
-import org.junit.Test;
-
 import com.vaadin.testbench.elements.NativeButtonElement;
 import com.vaadin.tests.tb3.MultiBrowserTest;
+import org.junit.Test;
 
 public class AccordionClipsContentTest extends MultiBrowserTest {
     @Override
@@ -48,6 +47,11 @@ public class AccordionClipsContentTest extends MultiBrowserTest {
 
         $(NativeButtonElement.class).first().click();
 
+        // Give the button time to pop back up in IE8.
+        // If this sleep causes issues, next best thing is to click outside the
+        // button to remove focus - needs new screenshots for all browsers.
+        Thread.sleep(10);
+
         compareScreen("button-clicked");
     }