Enable Clear-Site-Data web platform tests.

third_party/WebKit/LayoutTests/external/wpt/clear-site-data/support/echo-clear-site-data.py

Index: third_party/WebKit/LayoutTests/external/wpt/clear-site-data/support/echo-clear-site-data.py
diff --git a/third_party/WebKit/LayoutTests/external/wpt/clear-site-data/support/echo-clear-site-data.py b/third_party/WebKit/LayoutTests/external/wpt/clear-site-data/support/echo-clear-site-data.py
index e8ec8d55327c28339c7466fcf613ff784359f2e1..ab85002abb34874bb8300b47e21a25cab0c6133b 100644
--- a/third_party/WebKit/LayoutTests/external/wpt/clear-site-data/support/echo-clear-site-data.py
+++ b/third_party/WebKit/LayoutTests/external/wpt/clear-site-data/support/echo-clear-site-data.py
@@ -34,7 +34,7 @@ RESPONSE = """
 # embedder whether the data deletion succeeded.
 def main(request, response):
     types = [key for key in request.GET.keys()]
-    header = json.dumps({ "types": types })
+    header = ",".join("\"" + type + "\"" for type in types)
     return ([("Clear-Site-Data", header),
              ("Content-Type", "text/html")],
             RESPONSE)