Move destruction of WebRtcLogUploader to post threads teardown.

chrome/browser/media/webrtc_logging_handler_host.cc

Index: chrome/browser/media/webrtc_logging_handler_host.cc
diff --git a/chrome/browser/media/webrtc_logging_handler_host.cc b/chrome/browser/media/webrtc_logging_handler_host.cc
index e729588611bcf1d068516f2934b52386cbc5abae..e1919d2670c2bb17bd436916f522fb9ab448de55 100644
--- a/chrome/browser/media/webrtc_logging_handler_host.cc
+++ b/chrome/browser/media/webrtc_logging_handler_host.cc
@@ -294,7 +294,6 @@ void WebRtcLoggingHandlerHost::StartLoggingIfAllowed() {
           "simultaneuos logs has been reached.");
     return;
   }
-  system_request_context_ = g_browser_process->system_request_context();
   BrowserThread::PostTask(BrowserThread::IO, FROM_HERE, base::Bind(
       &WebRtcLoggingHandlerHost::DoStartLogging, this));
 }
@@ -439,7 +438,6 @@ void WebRtcLoggingHandlerHost::TriggerUploadLog(
   BrowserThread::PostTask(BrowserThread::FILE, FROM_HERE, base::Bind(
       &WebRtcLogUploader::LoggingStoppedDoUpload,
       base::Unretained(g_browser_process->webrtc_log_uploader()),
-      system_request_context_,
       Passed(&log_buffer_),
       kWebRtcLogSize,
       meta_data_,