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 52d4d549d286e92fe0e1f3592990811879a78a1b..306108271c8af68ee993e0aadcd6190bedb5f171 100644
--- a/chrome/browser/media/webrtc_logging_handler_host.cc
+++ b/chrome/browser/media/webrtc_logging_handler_host.cc
@@ -283,7 +283,6 @@ 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));
 }
@@ -415,7 +414,6 @@ 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_,