Add return-by-value implementations of blink::WebMediaPlayer::buffered()

media/base/pipeline.cc

Index: media/base/pipeline.cc
diff --git a/media/base/pipeline.cc b/media/base/pipeline.cc
index 9a7488094259402a467d4587d1b5c911c6676985..e177e188c90be6a6a5c9984415279555cdd8d48a 100644
--- a/media/base/pipeline.cc
+++ b/media/base/pipeline.cc
@@ -159,7 +159,7 @@ TimeDelta Pipeline::GetMediaTime() const {
   return clock_->Elapsed();
 }
 
-Ranges<TimeDelta> Pipeline::GetBufferedTimeRanges() {
+Ranges<TimeDelta> Pipeline::GetBufferedTimeRanges() const {
   base::AutoLock auto_lock(lock_);
   return buffered_time_ranges_;
 }