Add test expectation for http/tests/security/img-crossorigin-no-credentials-prompt.html

NOTRY=true
[email protected]
BUG=426078

Review URL: https://codereview.chromium.org/671983002

git-svn-id: svn://svn.chromium.org/blink/trunk@184209 bbb929c8-8fbe-4397-9dbb-9b2b20218538
diff --git a/third_party/WebKit/LayoutTests/TestExpectations b/third_party/WebKit/LayoutTests/TestExpectations
index 38c2506..81ca840 100644
--- a/third_party/WebKit/LayoutTests/TestExpectations
+++ b/third_party/WebKit/LayoutTests/TestExpectations
@@ -1493,3 +1493,5 @@
 
 #crbug.com/401377 [ Win Release ] http/tests/serviceworker/fetch-mixed-content.html [ Pass Timeout ]
 crbug.com/426047 http/tests/serviceworker/fetch-mixed-content.html [ Pass Timeout ]
+
+crbug.com/426078 [ Win7 ] http/tests/security/img-crossorigin-no-credentials-prompt.html [ Pass Timeout ]