Log error messages in windows video capture

content/browser/renderer_host/media/video_capture_controller.cc

Index: content/browser/renderer_host/media/video_capture_controller.cc
diff --git a/content/browser/renderer_host/media/video_capture_controller.cc b/content/browser/renderer_host/media/video_capture_controller.cc
index 4fd53a88fb610b1262b25baee9e3761b6633fa56..b8d8dd30d82b1ace6e632c82440af5b68ec4ad42 100644
--- a/content/browser/renderer_host/media/video_capture_controller.cc
+++ b/content/browser/renderer_host/media/video_capture_controller.cc
@@ -516,8 +516,13 @@ VideoCaptureController::VideoCaptureDeviceClient::OnIncomingCapturedVideoFrame(
 
 void VideoCaptureController::VideoCaptureDeviceClient::OnError(
     const std::string& reason) {
+  const std::string last_error_message =
+      logging::SystemErrorCodeToString(logging::GetLastSystemErrorCode());
+  const std::string log_message =
+      reason + ", OS message: " + last_error_message;
+  DLOG(ERROR) << log_message;

[tommi (sloooow) - chröme, 2014/08/27 14:46:18]

log_message could be a std::ostringstream which would reduce the amount of
std::string objects being created as a result of using operator+().

[magjed_chromium, 2014/08/27 17:03:27]

Done.

   MediaStreamManager::SendMessageToNativeLog(
-      "Error on video capture: " + reason);
+      "Error on video capture: " + log_message);

[tommi (sloooow) - chröme, 2014/08/27 14:46:18]

"Error on video capture: " could be made the first part of log_message which
would reduce one more std::string.

[magjed_chromium, 2014/08/27 17:03:27]

Done.

   BrowserThread::PostTask(BrowserThread::IO,
       FROM_HERE,
       base::Bind(&VideoCaptureController::DoErrorOnIOThread, controller_));