Fix flakiness of fast/forms/submit-change-fragment.html.

The test timed out in the following case:

1. document.location.search = "?n=v" requests a navigation.
2. Before the navigation happens, onload handler runTest() is executed.
3. document.forms.f.submit() navigates to
    ".../submit-change-fragment.html?n=v#firstaction"
4. Because the original document was ".../submit-change-fragment.html",
   onhashchange handler is NOT called.
5. No one calls testRunner.notifyDone().

This CL moves "?n=v" setting code to runTest(), and do early return to avoid the
form submission without "?n=v".

BUG=521860

Review URL: https://codereview.chromium.org/1302703002

git-svn-id: svn://svn.chromium.org/blink/trunk@200798 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/LayoutTests/TestExpectations

@@ -43,7 +43,6 @@ crbug.com/520736 [ Win7 ] media/W3C/video/networkState/networkState_during_progr
 
 crbug.com/521862 [ Linux Win ] storage/websql/read-transactions-running-concurrently.html [ Failure Pass ]
 crbug.com/521861 [ Debug ] media/track/tracklist-is-reachable-no-crash.html [ Crash Pass ]
-crbug.com/521860 fast/forms/submit-change-fragment.html [ Pass Timeout ]
 crbug.com/521859 http/tests/navigatorconnect/postmessage-from-worker.html [ Pass Timeout ]
 crbug.com/521858 [ Win7 ] http/tests/security/media-element-audio-source-node-same-origin.html [ Failure Pass ]
 crbug.com/521857 [ Win7 ] imported/web-platform-tests/IndexedDB/idbdatabase_createObjectStore10-1000ends.htm [ Pass Timeout ]

third_party/WebKit/LayoutTests/fast/forms/submit-change-fragment.html

@@ -5,10 +5,11 @@ if (window.testRunner) {
     testRunner.waitUntilDone();
 }
 
-if (document.location.href.indexOf("n=v") == -1)
-    document.location.search = "?n=v";
-
 function runTest() {
+    if (document.location.href.indexOf("n=v") == -1) {
+        document.location.search = "?n=v";
+        return;
+    }
     document.forms.f.action="#firstaction";
     document.forms.f.submit();
     document.forms.f.action="#secondaction";