Don't fire popstate event on initial document load

LayoutTests/fast/loader/stateobjects/resources/replacestate-in-iframe-window-child.html

Index: LayoutTests/fast/loader/stateobjects/resources/replacestate-in-iframe-window-child.html
diff --git a/LayoutTests/fast/loader/stateobjects/resources/replacestate-in-iframe-window-child.html b/LayoutTests/fast/loader/stateobjects/resources/replacestate-in-iframe-window-child.html
index c83f9c82804dc287b0b3d479e2c07fecd8596e52..7e682b9b106ec360f61373cea72d1f717100df4e 100644
--- a/LayoutTests/fast/loader/stateobjects/resources/replacestate-in-iframe-window-child.html
+++ b/LayoutTests/fast/loader/stateobjects/resources/replacestate-in-iframe-window-child.html
@@ -1,15 +1,13 @@
 <script>
-onunload = function() {
+window.onload = function() {
+  top.opener.windowLoaded();

[Jens Widell, 2014/01/16 08:16:20]

Since the window is navigated to a different top-level document and back, this
onload handler is called twice, and thus incorrectly "starts" the test again in
the middle.  Should have copied the "sessionStorage.beganTest" mechanism from
the old onpopstate instead of just this call.

This test case bug appears to be involved in the Windows-only crash found by the
trybots, but doesn't (of course) explain why we'd crash.

+}
+
+window.onunload = function() {
   // No page cache
 }
 
-onpopstate = function(e) {
-  if (!sessionStorage.beganTest) {
-      sessionStorage.beganTest = true; 
-      top.opener.windowLoaded();
-      return;
-  }
-  
+window.onpopstate = function(e) {
   alert("onpopstate");
   top.opener.notifyDone(window == parent ? "FAIL" : "PASS");
 }