Remove testRunner.display() from most compositing/ tests

LayoutTests/compositing/iframes/overlapped-nested-iframes.html

Index: LayoutTests/compositing/iframes/overlapped-nested-iframes.html
diff --git a/LayoutTests/compositing/iframes/overlapped-nested-iframes.html b/LayoutTests/compositing/iframes/overlapped-nested-iframes.html
index 0d84b27cec771481ce4e5b69ed993af1b570cc68..aaaeb626aed8ade8786e4188bcd0b9449c93a3bb 100644
--- a/LayoutTests/compositing/iframes/overlapped-nested-iframes.html
+++ b/LayoutTests/compositing/iframes/overlapped-nested-iframes.html
@@ -24,24 +24,14 @@
   <script type="text/javascript" charset="utf-8">
     if (window.testRunner) {
         testRunner.dumpAsText();
-        testRunner.waitUntilDone();
     }
 
     function doTest()
     {
-        // For some reason this delay is required for AppKit to not short-circuit the display.
-        window.setTimeout(function() {
-          window.scrollTo(0, 100);
-          // Force a paint, and give layers a chance to update.
-          if (window.testRunner)
-            testRunner.display();
-          window.setTimeout(function() {
-            if (window.testRunner) {
-                document.getElementById('layers').innerHTML = window.internals.layerTreeAsText(document);
-                testRunner.notifyDone();
-            }
-          }, 0);
-        }, 0);
+      window.scrollTo(0, 100);
+      if (window.testRunner) {
+          document.getElementById('layers').innerHTML = window.internals.layerTreeAsText(document);
+      }
     }
 
     window.addEventListener('load', doTest, false);