Log error messages in windows video capture

content/browser/renderer_host/media/video_capture_controller.cc

 // Copyright (c) 2012 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.
 
 #include "content/browser/renderer_host/media/video_capture_controller.h"
 
 #include <map>
 #include <set>
 
 #include "base/bind.h"
 #include "base/debug/trace_event.h"
 #include "base/metrics/histogram.h"
 #include "base/metrics/sparse_histogram.h"
 #include "base/stl_util.h"
+#include "base/strings/stringprintf.h"
 #include "content/browser/renderer_host/media/media_stream_manager.h"
 #include "content/browser/renderer_host/media/video_capture_manager.h"
 #include "content/common/gpu/client/gl_helper.h"
 #include "content/public/browser/browser_thread.h"
 #include "gpu/command_buffer/common/mailbox_holder.h"
 #include "media/base/video_frame.h"
 #include "media/base/video_util.h"
 #include "media/base/yuv_convert.h"
 #include "third_party/libyuv/include/libyuv.h"
 
@@ skipping 484 matching lines @@
           &VideoCaptureController::DoIncomingCapturedVideoFrameOnIOThread,
           controller_,
           buffer,
           buffer_format,
           frame,
           timestamp));
 }
 
 void VideoCaptureController::VideoCaptureDeviceClient::OnError(
     const std::string& reason) {
-  MediaStreamManager::SendMessageToNativeLog(
-      "Error on video capture: " + reason);
+  const std::string log_message = base::StringPrintf(
+      "Error on video capture: %s, OS message: %s",

[perkj_chrome, 2014/08/29 14:17:34]

Can we also log the error code?

[tommi (sloooow) - chröme, 2014/08/30 17:39:33]

The 'last error' on the thread is being included indirectly via
GetLastSystemErrorCode, but it looks like the OnError method doesn't support
providing an alternate error code.  Perhaps the code is expected to be included
in the error message when applicable?

[magjed_chromium, 2014/09/01 08:34:14]

See message.

+      reason.c_str(),
+      logging::SystemErrorCodeToString(
+          logging::GetLastSystemErrorCode()).c_str());
+  DLOG(ERROR) << log_message;
+  MediaStreamManager::SendMessageToNativeLog(log_message);
   BrowserThread::PostTask(BrowserThread::IO,
       FROM_HERE,
       base::Bind(&VideoCaptureController::DoErrorOnIOThread, controller_));
 }
 
 void VideoCaptureController::VideoCaptureDeviceClient::OnLog(
     const std::string& message) {
   MediaStreamManager::SendMessageToNativeLog("Video capture: " + message);
 }
 
@@ skipping 145 matching lines @@
   }
   return NULL;
 }
 
 int VideoCaptureController::GetClientCount() {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   return controller_clients_.size();
 }
 
 }  // namespace content