To M59: Add MediaError.message

media/blink/webmediaplayer_impl.cc

Index: media/blink/webmediaplayer_impl.cc
diff --git a/media/blink/webmediaplayer_impl.cc b/media/blink/webmediaplayer_impl.cc
index 83b6df200c12fd6bbd6a6461d75a2dbc43e2523e..00c5d1d370877260edbd931e7022eaeb41fcba72 100644
--- a/media/blink/webmediaplayer_impl.cc
+++ b/media/blink/webmediaplayer_impl.cc
@@ -783,9 +783,9 @@ WebMediaPlayer::ReadyState WebMediaPlayerImpl::GetReadyState() const {
   return ready_state_;
 }
 
-blink::WebString WebMediaPlayerImpl::GetErrorMessage() {
+blink::WebString WebMediaPlayerImpl::GetErrorMessage() const {
   DCHECK(main_task_runner_->BelongsToCurrentThread());
-  return blink::WebString::FromUTF8(media_log_->GetLastErrorMessage());
+  return blink::WebString::FromUTF8(media_log_->GetErrorMessage());
 }
 
 blink::WebTimeRanges WebMediaPlayerImpl::Buffered() const {