Fix recursion bug in blocking a fetch and add a test

headless/public/util/url_fetcher.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef HEADLESS_PUBLIC_UTIL_URL_FETCHER_H_
 #define HEADLESS_PUBLIC_UTIL_URL_FETCHER_H_
 
 #include <stddef.h>
 #include <string>
 #include <vector>
@@ skipping 17 matching lines @@
  public:
   URLFetcher() {}
   virtual ~URLFetcher() {}
 
   // Interface for reporting the fetch result.
   class ResultListener {
    public:
     ResultListener() {}
 
     // Informs the listener that the fetch failed.
-    virtual void OnStartError(net::Error error) = 0;
+    virtual void OnFetchStartError(net::Error error) = 0;
 
     // Informs the listener that the fetch succeeded and returns the HTTP
     // headers and the body.  NOTE |body| must be owned by the caller and remain
     // valid until the fetcher is destroyed,
     virtual void OnFetchComplete(
         const GURL& final_url,
         int http_response_code,
         scoped_refptr<net::HttpResponseHeaders> response_headers,
         const char* body,
         size_t body_size) = 0;
@@ skipping 17 matching lines @@
                           const net::HttpRequestHeaders& request_headers,
                           ResultListener* result_listener) = 0;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(URLFetcher);
 };
 
 }  // namespace headless
 
 #endif  // HEADLESS_PUBLIC_UTIL_URL_FETCHER_H_