Remove ChromotingHostContext from DnsBlackholeChecker.

remoting/host/dns_blackhole_checker.h

 // Copyright (c) 2012 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 REMOTING_HOST_DNS_BLACKHOLE_CHECKER_H_
 #define REMOTING_HOST_DNS_BLACKHOLE_CHECKER_H_
 
 #include "net/url_request/url_fetcher_delegate.h"
 
 #include "base/callback.h"
 
+namespace net {
+class URLRequestContextGetter;
+}  // namespace net
+
 namespace remoting {
 
 // This is the default prefix that is prepended to the kTalkGadgetUrl to form
 // the complete talkgadget URL used by the host. Policy settings allow admins
 // to change the prefix that is used.
 extern const char kDefaultHostTalkGadgetPrefix[];
 
-class ChromotingHostContext;
-
 class DnsBlackholeChecker : public net::URLFetcherDelegate {
  public:
-  DnsBlackholeChecker(ChromotingHostContext* context,
-                      std::string talkgadget_prefix);
+  DnsBlackholeChecker(
+      scoped_refptr<net::URLRequestContextGetter> url_request_context_getter,
+      std::string talkgadget_prefix);
   virtual ~DnsBlackholeChecker();
 
   // net::URLFetcherDelegate interface.
   virtual void OnURLFetchComplete(const net::URLFetcher* source) OVERRIDE;
 
   // Initiates a check the verify that the host talkgadget has not been "DNS
   // blackholed" to prevent connections. If this is called again before the
   // callback has been called, then the second call is ignored.
   void CheckForDnsBlackhole(const base::Callback<void(bool)>& callback);
 
  private:
-  ChromotingHostContext* context_;
+  // URL request context getter to use to create the URL fetcher.
+  scoped_refptr<net::URLRequestContextGetter> url_request_context_getter_;
 
   // URL fetcher used to verify access to the host talkgadget.
   scoped_ptr<net::URLFetcher> url_fetcher_;
 
   // The string pre-pended to '.talkgadget.google.com' to create the full
   // talkgadget domain name for the host.
   std::string talkgadget_prefix_;
 
   // Called with the results of the connection check.
   base::Callback<void(bool)> callback_;
 
   DISALLOW_COPY_AND_ASSIGN(DnsBlackholeChecker);
 };
 
 }  // namespace remoting
 
 #endif  // REMOTING_HOST_DNS_BLACKHOLE_CHECKER_H_