Implement browser-side logging to WebRtc log

chrome/browser/media/webrtc_logging_handler_host.h

Index: chrome/browser/media/webrtc_logging_handler_host.h
diff --git a/chrome/browser/media/webrtc_logging_handler_host.h b/chrome/browser/media/webrtc_logging_handler_host.h
index 5f7f5a42d699a671b81e65d9c197db6026e276a3..d60dfc61d24641c8fb0e9f6fd6e3858e24a28a06 100644
--- a/chrome/browser/media/webrtc_logging_handler_host.h
+++ b/chrome/browser/media/webrtc_logging_handler_host.h
@@ -61,6 +61,9 @@ class WebRtcLoggingHandlerHost : public content::BrowserMessageFilter {
   // called on the IO thread.
   void DiscardLog(const GenericDoneCallback& callback);
 
+  // Adds a message to the log.
+  void LogMessage(const std::string& message);
+
   // May be called on any thread. |upload_log_on_render_close_| is used
   // for decision making and it's OK if it changes before the execution based
   // on that decision has finished.
@@ -99,6 +102,8 @@ class WebRtcLoggingHandlerHost : public content::BrowserMessageFilter {
   virtual bool OnMessageReceived(const IPC::Message& message,
                                  bool* message_was_ok) OVERRIDE;
 
+  // Handles log message requests from both renderer process and browser
+  // process.
   void OnAddLogMessage(const std::string& message);
   void OnLoggingStoppedInRenderer();