Cast channel: Add cast.channel.getLogs extension API.

extensions/browser/api/cast_channel/logger.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 EXTENSIONS_BROWSER_API_CAST_CHANNEL_LOGGER_H_
 #define EXTENSIONS_BROWSER_API_CAST_CHANNEL_LOGGER_H_
 
 #include <deque>
 #include <map>
 
@@ skipping 52 matching lines @@
 
   // For AUTH_CHALLENGE_REPLY event.
   void LogSocketChallengeReplyEvent(int channel_id,
                                     const AuthResult& auth_result);
 
   void LogSocketEventForMessage(int channel_id,
                                 proto::EventType event_type,
                                 const std::string& message_namespace,
                                 const std::string& details);
 
-  // Assembles logs collected so far and return it as a serialized Log proto.
-  // |output|: Where serialized contents will be assigned to.
-  // Returns true if serialization is successful.
-  // Contents in |output| is valid only if function returns true.
-  // TODO(imcheng): Add compression.
-  bool LogToString(std::string* output) const;
+  // Assembles logs collected so far and return it as a serialized Log proto,
+  // compressed in gzip format.
+  // If serialization or compression failed, returns a NULL pointer.
+  // |length|: If successful, assigned with size of compressed content.
+  scoped_ptr<char[]> GetLogs(size_t* length) const;
 
   // Clears the internal map.
   void Reset();
 
   // Returns the last errors logged for |channel_id|.  If the the logs for
   // |channel_id| are evicted before this is called, returns a LastErrors with
   // no errors.  This may happen if errors are logged and retrieved in different
   // tasks.
   LastErrors GetLastErrors(int channel_id) const;
 
@@ skipping 44 matching lines @@
 
   base::ThreadChecker thread_checker_;
 
   DISALLOW_COPY_AND_ASSIGN(Logger);
 };
 }  // namespace cast_channel
 }  // namespace api
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_API_CAST_CHANNEL_LOGGER_H_