Build correct URL for cacheinvalidation endpoint.

sync/notifier/gcm_network_channel.h

 // Copyright 2014 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 SYNC_NOTIFIER_GCM_NETWORK_CHANNEL_H_
 #define SYNC_NOTIFIER_GCM_NETWORK_CHANNEL_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 31 matching lines @@
   virtual void UpdateCredentials(const std::string& email,
                                  const std::string& token) OVERRIDE;
 
   // URLFetcherDelegate implementation.
   virtual void OnURLFetchComplete(const net::URLFetcher* source) OVERRIDE;
 
  protected:
   void ResetRegisterBackoffEntryForTest(
       const net::BackoffEntry::Policy* policy);
 
+  virtual GURL BuildUrl(const std::string& registration_id);
+
  private:
+  friend class GCMNetworkChannelTest;
   void Register();
   void OnRegisterComplete(const std::string& registration_id,
                           gcm::GCMClient::Result result);
   void RequestAccessToken();
   void OnGetTokenComplete(const GoogleServiceAuthError& error,
                           const std::string& token);
-  GURL BuildUrl();
+  // Base64 encoding/decoding with URL safe alphabet.
+  // http://tools.ietf.org/html/rfc4648#page-7
+  static void Base64EncodeURLSafe(const std::string& input,
+                                  std::string* output);
+  static bool Base64DecodeURLSafe(const std::string& input,
+                                  std::string* output);
 
   scoped_refptr<net::URLRequestContextGetter> request_context_getter_;
   scoped_ptr<GCMNetworkChannelDelegate> delegate_;
 
   // Message is saved until all conditions are met: there is valid
   // registration_id and access_token.
   std::string cached_message_;
 
   // Access token is saved because in case of auth failure from server we need
   // to invalidate it.
   std::string access_token_;
 
   // GCM registration_id is requested one at startup and never refreshed until
   // next restart.
   std::string registration_id_;
   scoped_ptr<net::BackoffEntry> register_backoff_entry_;
 
   scoped_ptr<net::URLFetcher> fetcher_;
 
   base::WeakPtrFactory<GCMNetworkChannel> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(GCMNetworkChannel);
 };
 
 }  // namespace syncer
 
 #endif  // SYNC_NOTIFIER_GCM_NETWORK_CHANNEL_H_