Simplify the magic required to create IPC message headers a bit.

ipc/ipc_logging.h

 // Copyright (c) 2009 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 IPC_IPC_LOGGING_H_
 #define IPC_IPC_LOGGING_H_
 #pragma once
 
 #include "ipc/ipc_message.h"  // For IPC_MESSAGE_LOG_ENABLED.
 
 #ifdef IPC_MESSAGE_LOG_ENABLED
 
 #include <vector>
 
+#include "base/hash_tables.h"
 #include "base/message_loop.h"
 #include "base/scoped_ptr.h"
 #include "base/singleton.h"
 
+// Logging function. |name| is a string in ASCII and |params| is a string in
+// UTF-8.
+typedef void (*LogFunction)(std::string* name,
+                            const IPC::Message* msg,
+                            std::string* params);
+
+typedef base::hash_map<uint32, LogFunction > LogFunctionMap;
+
 namespace IPC {
 
 class Message;
 
 // One instance per process.  Needs to be created on the main thread (the UI
 // thread in the browser) but OnPreDispatchMessage/OnPostDispatchMessage
 // can be called on other threads.
 class Logging {
  public:
   // Implemented by consumers of log messages.
@@ skipping 35 matching lines @@
   // sandbox can add them to to the policy.  If true, gets the name of the
   // enabled event, if false, gets the name of the disabled event.
   static std::wstring GetEventName(bool enabled);
 
   // Like the *MsgLog functions declared for each message class, except this
   // calls the correct one based on the message type automatically.  Defined in
   // ipc_logging.cc.
   static void GetMessageText(uint32 type, std::string* name,
                              const Message* message, std::string* params);
 
-  // Logging function. |name| is a string in ASCII and |params| is a string in
-  // UTF-8.
-  typedef void (*LogFunction)(uint32 type,
-                             std::string* name,
-                             const Message* msg,
-                             std::string* params);
+  static void set_log_function_map(LogFunctionMap* functions) {
+    log_function_map_ = functions;
+  }
 
-  static void SetLoggerFunctions(LogFunction *functions);
+  static LogFunctionMap* log_function_map() {
+    return log_function_map_;
+  }
 
  private:
   friend struct DefaultSingletonTraits<Logging>;
   Logging();
 
   void OnSendLogs();
   void Log(const LogData& data);
 
   bool enabled_;
   bool enabled_on_stderr_;  // only used on POSIX for now
 
   std::vector<LogData> queued_logs_;
   bool queue_invoke_later_pending_;
 
   Message::Sender* sender_;
   MessageLoop* main_thread_;
 
   Consumer* consumer_;
 
-  static LogFunction *log_function_mapping_;
+  static LogFunctionMap* log_function_map_;
 };
 
 }  // namespace IPC
 
 #endif // IPC_MESSAGE_LOG_ENABLED
 
 #endif  // IPC_IPC_LOGGING_H_